Entire Hemisphere Research Articles

Controlled short-period orbits around Earth-Moon equilateral libration points for Lunar Occultations

This paper proposes a framework for a satellite mission with the goal to perform Lunar Occultations within the context of the circular restricted three-body problem (CR3BP) of the Earth-Moon system. This is achieved by exploiting the geometrical relationships between the Earth, Moon, and a spacecraft orbiting around L4. Additionally, it examines the viability of a linear state-feedback control policy to stabilize short-period orbits under the presence of the gravitational effect of the Sun, Solar radiation pressure, and the Lunar orbital eccentricity, which is not accounted for in the CR3BP dynamics. Given the unprecedented NUV angular resolution achieved by a spacecraft at L4, this research proposes a framework for a remote sensing observatory for Solar activity, thereby enabling the monitoring of the entire hemisphere of Solar radiation, and to study different astrophysical issues via Lunar Occultations.

Sensitivity of seasonal circulation response to snow reduction in the Northern Hemisphere and Eurasia and its impact on Eurasian climate

In this study, we analyze the impact of reduced snow cover in the Northern Hemisphere on the atmosphere and if the atmospheric response depends on the model resolution. We use the atmospheric component of the global climate model EC-Earth and perform three experiments: in the first experiment, we reduce the snow cover in the entire Northern Hemisphere by reducing the snow albedo to a constant value of 0.3, in the second experiment, we reduce the snow albedo only over Eurasia, and the third experiment is the control run using normal snow conditions. All experiments are integrated over the period 1980–2015 at standard resolution (~ 80 km) and high resolution (~ 40 km). Experiments comprise 11 and 5 ensemble members at standard resolution and high resolution, respectively. Reducing the snow albedo in the Northern Hemisphere leads to 5–10% snow cover reduction in winter and spring. Significant warm responses are found over northern Eurasia in spring and summer with a warm response reaching 3 °C. Similar but weaker warm temperature responses are found in the middle and upper troposphere (up to 2 °C) and reversed temperature responses in the stratosphere (up to – 2 °C), particularly over eastern Eurasia. This is closely associated with westerly jet flow response which is enhanced at high-latitude and weakened at low-latitude in winter and spring over eastern Eurasia. Reduced snow cover leads to warmer surface temperatures that accelerate snow-melting and further lead to different snow-hydrological responses in western and eastern Eurasia and more precipitation occurs over eastern Eurasia (increasing 10–20%), particularly in the Siberian region. When the snow albedo is reduced only in the Eurasian sector, the surface response pattern resembles the results of the Northern Hemisphere experiment. The warm response is slightly weakened about 0.25–0.5 °C over Eurasia and significantly weakened outside of Eurasia. However, the upper air circulation response is much less pronounced over Eurasia. The impact of resolution on the mean surface field response is small yet it is more pronounced on the large-scale circulation response, particularly in spring and winter.

Todd's paralysis due to hyperperfusion syndrome after carotid endarterectomy mimicking postoperative stroke.

Todd's paralysis is a neurological deficit that is observed in <10% of patients following epileptic seizures. Cerebral hyperperfusion syndrome (CHS) is a rare complication following carotid endarterectomy (CEA), seen in 0-3% of the patients, characterized by focal neurological deficit, headache, disorientation, and sometimes seizures. In this case report, we present a case of CHS after CEA followed by seizures and Todd's paralysis that mimicked postoperative stroke. A 75-year-old female patient was admitted for CEA of the right internal carotid artery, following a transient ischemic attack two months prior. Four hours after CEA with graft interposition, the patient suffered a temporary weakness of the left arm and leg followed by generalized spasms within a few seconds. CT angiography showed regular patency of the carotid arteries and the graft, and brain CT showed no sign of oedema, ischemia or hemorrhage. However, left-sided hemiplegia occurred following the seizure, and the patient suffered four more seizures over the next 48 hours, with persisting hemiplegia. On the second postoperative day, the motor skills of the left side fully recovered, and the patient was communicative, and of orderly mental status. Brain CT performed on the third postoperative day showed entire right hemisphere oedema. A moderate hemiparesis with seizures as a consequence of CHS after CEA has been described, however in all cases with seizures and hemiplegia, the underlying cause was always a verified stroke or intracerebral hemorrhage. This case highlights the importance of considering Todd's paralysis in patients with seizures after CEA due to CHS and prolonged periods of hemiplegia after the seizures.

CALIOP-Based Evaluation of Dust Emissions and Long-Range Transport of the Dust from the Aral−Caspian Arid Region by 3D-Source Potential Impact (3D-SPI) Method

The average monthly profiles of the dust extinction coefficient (ε) were analyzed according to the CALIOP lidar data from 2006–2021 for 24 cells (size of 2° × 5°) in the Aral-Caspian arid region (ACAR; 38–48°N, 50–70°E). Using the NOAA HYSPLIT_4 trajectory model and the NCEP GDAS1 gridded (resolution of 1° × 1°) archive of meteorological data, the array of &gt;1 million 10-day forward trajectories (FTs) of air particles that started from the centers of the ACAR cells was calculated. On the basis of the FT array, the average seasonal heights of the mixed layer (ML) for the ACAR cells were reconstructed. Estimates of the average seasonal dust optical depth (DOD) were obtained for ACAR’s lower troposphere, for ACAR’s ML (“dust emission layer” (EL)), and for the lower troposphere above the ML (“dust transit layer” (TL)) above each of the ACAR cells. Using the example of ACAR, it is shown that the analysis of DOD for the EL, TL and the surface layer (SL; the first 200 m AGL) makes it possible to identify dusty surfaces that are not detected on DOD diagrams for the entire atmospheric column, as well as regions where the regular transport of aged dust from remote sources can generate false sources. Based on FT array, the fields of the potential contribution of both the ACAR’s dust transit and the ACAR’s dust emission layers as well as of the entire ACAR’s lower troposphere into the DOD of the surrounding and remote regions are retrieved using the original method of potential impact of a three-dimensional source (3D-PSI). It has been found out that ACAR dust spreads over almost the entire Northern Hemisphere; the south and southeast regions of the ACAR are subject to the maximum impact of the ACAR dust. Quantitative estimates of the potential contribution of ACAR dust to the regional DODs are given for a number of control sites in the Northern Hemisphere. The results could be useful for climatological studies.

Mowat-Wilson Syndrome; 3 Cases with Characteristic EEG Findings (P3-1.008)

<h3>Objective:</h3> This is a case-based review of clinical manifestations and electroencephalogram findings of Mowat-Wilson Syndrome (MWS) <h3>Background:</h3> MWS is a rare multi system disorder due to ZEB2 gene defects. The main feature of MWS is epilepsy; 75–80% prevalence was noted in prior case series. <h3>Design/Methods:</h3> Children with known diagnoses of MWS were identified in the Pediatric Epilepsy Clinic attached to a tertiary-care pediatric hospital through retrospective chart review. Literature was searched with keywords ‘Mowat-Wilson Syndrome’ and ‘EEG features’ <h3>Results:</h3> Three children with MWS were identified. All cases were heterozygous for ZEB2 gene mutations and had brain imaging and electroencephalograms available for review. <h3>Patient A (11 year-old):</h3> Semiology was generalized and focal (oral automatisms and left-hand flapping). On electroencephalogram there was continuous 2–3 Hz spike-and-wave activity during sleep with left predominance (left frontal at first, but then involving the entire left hemisphere over the years), and intermittent 2.5–3 Hz high-voltage generalized spike-and-wave bursts during wakefulness <h3>Patient B (7 year-old):</h3> Semiology was generalized and focal (right-sided hypotonia and leftwards gaze). On electroencephalogram there were frequent 2–3 Hz poly-spike-and-wave discharges with left frontal-central predominance during sleep, and seizures stemming from right temporal and parieto-occipital areas during status epilepticus <h3>Patient C (4 year-old):</h3> Semiology was generalized. On electroencephalogram there were frequent bi-occipital sharp-and-slow-wave discharges as well as infrequent bursts of high-amplitude generalized 1–2 Hz spike-and-waves <h3>Conclusions:</h3> Electroencephalograms of 2 of 3 patients had continuous spike-waves in sleep (CSWS), even as seizure burden and semiology differed. While there was no CSWS in Patient C, there were sharp-and-slow-wave discharges during wakefulness. It is possible that due to Patient C’s younger age, the EEG has not progressed to develop full CSWS. Indeed, in Patient A, there was a clear progression of EEG abnormalities as the child grew older. This leads these authors to believe that CSWS seems to be distinctly common among Mowat-Wilson. <b>Disclosure:</b> Dr. Shahab has nothing to disclose. Dr. Anilkumar has received publishing royalties from a publication relating to health care.

Deep Brain Stimulation in Hemimegalencephaly with Medically Intractable Epilepsy: A Case Report (P5-1.010)

<h3>Objective:</h3> To highlight a unique case of medically intractable epilepsy secondary to hemimegalencephaly responsive to deep brain stimulation (DBS). <h3>Background:</h3> Hemimegalencephaly is a rare congenital disorder with overgrowth of a partial or entire cerebral hemisphere. This is seen in approximately 0.2% of childhood epilepsy and often leads to refractory seizures. In medically intractable cases, a hemispherectomy is considered to remove the epileptogenic focus. <h3>Design/Methods:</h3> Case report. <h3>Results:</h3> A 22-year-old right handed male presented with medically intractable focal epilepsy secondary to right hemimegalencephaly. He developed convulsive seizures with gustatory auras at 9 years old. He had a normal birth history, but delayed cognitive impairment. Initial MRI brain was read as normal, however his pediatric neurologist noted right hemimegalencephaly and he was trialed on antiseizure medications (ASM). This included levetiracetam, oxcarbazepine, valproic acid, clobazam, and lacosamide with initial response; however, efficacy waned over time. He later had focal seizures with impaired awareness and generalized tonic-clonic seizures. He was admitted to the epilepsy monitoring unit and a focal epilepsy with right fronto-central focus was observed. Repeat MRI brain and PET scan in 2018 revealed a right hemimegalencephaly that on further review traced back to imaging from 2009. Genetic testing was unrevealing. Seizures remained medically intractable and a vagus nerve stimulation (VNS) device was implanted with failed seizure control. He subsequently underwent DBS with bilateral lead placements in the anterior nucleus of the thalamus (ANT). In combination with ASMs, he reported a 60–70% seizure reduction. <h3>Conclusions:</h3> Hemimegalencephaly can occur in isolation or in association with syndromes such as tuberous sclerosis, Klippel-Trenaunay, or neurofibromatosis. While there is no cure, the goal is to reduce seizures with ASMs or hemispherectomy in refractive pediatric cases. Given the absence of motor deficits, hemispherectomy was not considered. This is a novel case of DBS being utilized in the management of hemimegalencephaly. <b>Disclosure:</b> Dr. Sivakumar has nothing to disclose. Dr. Ahmed has nothing to disclose. Dr. Hakimi has nothing to disclose.

Teaching NeuroImages: Magnetic resonance perfusion and diffusion findings in hemiplegic migraine

A 6-year-old boy presented with acute onset of left-sided weakness and homonymous hemianopia in the setting of 3 days of severe, unilateral, pulsating headache. MRI 3 hours after symptom onset showed hypoperfusion of the entire right hemisphere, with foci of diffusion restriction predominantly involving the right parietal lobe with apparent diffusion coefficient correlate (figure). He gradually improved and was discharged with no neurologic deficits. He was discovered to have a strong family history of hemiplegic migraine.

Brain structure, phenotypic and genetic correlates of reading performance.

Reading is an evolutionarily recent development that recruits and tunes brain circuitry connecting primary- and language-processing regions. We investigated whether metrics of the brain's physical structure correlate with reading performance and whether genetic variants affect this relationship. To this aim, we used the Adolescent Brain Cognitive Development dataset (n = 9,013) of 9-10-year-olds and focused on 150 measures of cortical surface area (CSA) and thickness. Our results reveal that reading performance is associated with nine measures of brain structure including relevant regions of the reading network. Furthermore, we show that this relationship is partially mediated by genetic factors for two of these measures: the CSA of the entire left hemisphere and, specifically, of the left superior temporal gyrus CSA. These effects emphasize the complex and subtle interplay between genes, brain and reading, which is a partly heritable polygenic skill that relies on a distributed network.

Climate-influenced boreotropical survival and rampant introgressionsexplain the thriving of New World grapes in the north temperate zone.

The north temperate region was characterized by a warm climate and a rich thermophilic flora before the Eocene, but early diversifications of the temperate biome under global climate change and biome shift remain uncertain. Moreover, it is becoming clear that hybridization/introgression is an important driving force of speciation in plant diversity. Here, we applied analyses from biogeography and phylogenetic networks to account for both introgression and incomplete lineage sorting based on genomic data from the New World Vitis, a charismatic component of the temperate North American flora with known and suspected gene flow among species. Biogeographic inference and fossil evidence suggest that the grapes were widely distributed from North America to Europe during the Paleocene to the Eocene, followed by widespread extinction and survival of relicts in the tropical New World. During the climate warming in the early Miocene, a Vitis ancestor migrated northward from the refugia with subsequent diversification in the North American region. We found strong evidence for widespread incongruence and reticulate evolution among nuclear genes within both recent and ancient lineages of the New World Vitis. Furthermore, the organellar genomes showed strong conflicts with the inferred species tree from the nuclear genomes. Our phylogenomic analyses provided an important assessment of the wide occurrence of reticulate introgression in the New World Vitis, which potentially represents one of the most important mechanisms for the diversification of Vitis species in temperate North America and even the entire temperate Northern Hemisphere. The scenario we report here may be a common model of temperate diversification of flowering plants adapted to the global climate cooling and fluctuation in the Neogene.

Abstract Number ‐ 54: First Fully Automated Robotic Transcranial Doppler Optimization of Cerebral Blood Flow During Cardiac Revascularization Surgery

Introduction Current technologies including EEG and near infrared pulse oximetry for non‐invasive monitoring of cerebral blood flow during cardiac surgery have proven inadequate for perioperative stroke risk mitigation. Cerebral arterial flow velocity is an excellent indicator of cerebral blood flow making transcranial doppler ultrasound (TCD) an excellent alternative technology for operating room continuous cerebral monitoring. To date, TCD utilization in the operating room has been limited due to frequent movement‐related loss of signal requiring nearly continuous manual probe readjustment. The recent development of fully autonomous robotic TCD (aTCD) has overcome these technical limitations, opening the door for real‐time continuous noninvasive cerebral blood flow monitoring with simultaneous emboli detection. Methods A 47‐year‐old female patient was found to have preoperative complete occlusion of the proximal brachiocephalic artery producing a double cerebral steal phenomenon with retrograde flow in the right internal carotid and vertebral arteries into the subclavian. A preoperative aTCD study disclosed baseline markedly diminished blood flow in the right middle cerebral artery (MCA) fed exclusively by small‐diameter collaterals via the circle of Willis.Intraoperatively, robotic aTCD was used to continuously monitor blood flow in the bilateral MCAs and perform emboli detection. In response to movement‐related signal loss, the robotic aTCD autonomously adjusted the probe position to maintain continuous MCA insonation. Results Shortly after intubation, a small drop in mean arterial pressure led to a near‐total loss of cerebral perfusion to the entire right hemisphere. This perfusion decrease was detected by aTCD, triggering the anesthesiologist to rapidly correct blood pressure to ensure adequate cerebral perfusion as confirmed by the robotic system. The patient was then placed on bypass pump with deployment of a temporary Y‐graft from the pump to the subclavian artery distal to the vertebral branch point and to the aorta to temporarily reverse the double cerebral steal. Coronary bypass was then performed, throughout which cerebral flow velocities were monitored continuously with aTCD and maintained in the safe cerebral perfusion range by adjusting pump pressures. Following a three‐vessel coronary bypass graft, permanent brachiocephalic artery bypass grafts were placed from the proximal aorta to the right subclavian and the proximal common carotid artery.Postoperative aTCD disclosed correction of the previously diminished blood flow detected in the right MCA preoperatively. Brain MRI postoperatively confirmed the absence of acute stroke. Conclusions This case represents the first use of robotic aTCD for real time continuous cerebral blood flow monitoring and optimization during complex cardiac surgery. Our experience suggests that aTCD may improve patient outcomes, particularly during high‐risk cardiac surgical and interventional procedures. Further studies of this promising technology are now needed.

EFFECTIVE DIAGNOSTIC TECHNIQUES IN BORRELIA BURGDORFERI INFESTATION IN DOGS

Borreliosis or Lyme disease is a disease transmitted by ixodidae ticks during feeding on blood (Ixodes pacificus and Ixodes scapularis in the USA, Ixodes persulcatus in Asia, Ixodes ricinus in Europe) and is widespread in the entire northern hemisphere. In Romania, the geographic distribution and prevalence of Borrelia burgdorferi sensu lato was 1.4% in 41 counties, with a prevalence between 0.75–18.8%. B. burgdorferi sensu lato. had a prevalence of 3.8%, being found inside ticks in 55 of 183 localities. Successful treatment and full recovery can only be achieved through early diagnosis. The clinical and serologic diagnosis of Lyme disease is particularly difficult because of the phenotypic heterogeneity within and among spirochete species. A case study is presented in this paper: an eight-year-old male Yorkshire terrier dog, which was diagnosed positive for Lyme disease, based on a test which uses a peptide called C6 and which comes from the VlsE protein of B. burgdorferi, used to detect antibodies in dogs. The results demonstrate the reliability of the commercial SNAP 4Dx Plus Test for B. burgdorferi, which uses C6 to differentiate antibodies produced by natural infection from antibodies formed after vaccination. In addition, using real-time PCR, the diagnosis was negative, confirming the results from the literature, according to which the PCR technique is only recommended for research, the positivity percentage being low, especially when the sample is blood (0.1%). We conclude that the tests for the detection of antibodies specific to Lyme disease are recommended and useful.

The first application of intraoperative mri for analysis of cerebral perfusion in surgical brain revascularization

Effectiveness of surgical revascularization in patients with chronic cerebral ischemia depends on restoration of circulation in the damaged artery. Modern methods do not take into account dynamic changes in cerebral perfusion after extra-intracranial microvascular anastomosis (EICMA) and do not allow timely localizing the areas of persistent perfusion deficit. We propose a new method for determining the tactics of surgical cerebral revascularization based on intraoperative MRI (iMRI) perfusion data. This method provides the earliest information on intraoperative brain reperfusion. To develop the principles of dynamic assessment of cerebral blood flow using intraoperative ASL perfusion during surgical revascularization in patients with chronic cerebral ischemia and to determine the indications for additional anastomoses. Surgical revascularization with intraoperative MRI perfusion was performed in 27 patients between March 2022 and April 2023. There were 10 patients with post-thrombotic occlusion of internal carotid artery, 4 patients with occlusion of middle cerebral artery and 13 patients with moyamoya disease. All patients underwent MRI before surgery. After imposing the first EICMA, all patients underwent ASL perfusion for analysis of residual hypoperfusion zones, signs of local hyperperfusion and indications or contraindications for additional revascularization with the second donor branch. In all cases, iMRI made it possible to determine the tactics of brain revascularization using one or two EICMA. In 17 cases, ASL perfusion confirmed the targeted improvement of cerebral blood flow (CBF) in the entire hemisphere or middle cerebral artery basin. Only one EICMA was imposed in these cases. In 10 cases, a single anastomosis was insufficient for restoration of blood flow. These patients underwent additional revascularization with the second donor branch (35.7%). In all cases, we achieved significant quantitative improvement in CBF and volume of brain tissue with restored blood flow (ASPECTS scale). A single EICMA was followed by increase in CBF and areas of restored blood flow by almost 2 times (22.7±9.6 ml/100 g/min and 4.7±1.8 scores (ASPECTS) before surgery vs. 39.4±16.4 ml/100 g/min and 4.7±1.8 scores after EICMA). In the double EICMA group, these parameters increased by almost 3 times (18±3.1 ml/100 g/min and 3.8±0.9 scores before surgery vs. 57±11.4 ml/100 g/min and 7.7±1.5 scores after double EICMA). All patients had no complications. Neurological status improved immediately after surgery in 9 patients (33.3%), stable postoperative period was observed in 12 cases (44.4%). Six (22.2%) patients had transient neurological deficit associated with hyperperfusion syndrome that regressed within a few days after surgery. There were no persistent ischemic complications. Intraoperative ASL perfusion is an effective and informative tool for determining the degree of restoration of blood flow. We can timely adjust surgical strategy, determine the indications or contraindications for additional revascularization and exclude early ischemic complications using this method.

Topographically Localized Modulation of Tectal Cell Spatial Tuning by Complex Natural Scenes.

The tuning properties of neurons in the visual system can be contextually modulated by the statistics of the area surrounding their receptive field (RF), particularly when the surround contains natural features. However, stimuli presented in specific egocentric locations may have greater behavioral relevance, raising the possibility that the extent of contextual modulation may vary with position in visual space. To explore this possibility, we utilized the small size and optical transparency of the larval zebrafish to describe the form and spatial arrangement of contextually modulated cells throughout an entire tectal hemisphere. We found that the spatial tuning of tectal neurons to a prey-like stimulus sharpens when the stimulus is presented against a background with the statistics of complex natural scenes, relative to a featureless background. These neurons are confined to a spatially restricted region of the tectum and have receptive fields centered within a region of visual space in which the presence of prey preferentially triggers hunting behavior. Our results suggest that contextual modulation of tectal neurons by complex backgrounds may facilitate prey-localization in cluttered visual environments.

Characterization of the spatial distribution of metals and profile of metalloprotein complexes in a mouse model of repetitive mild traumatic brain injury.

Metal dyshomeostasis is a well-established consequence of neurodegenerative diseases and traumatic brain injury. While the significance of metals continues to be uncovered in many neurological disorders, their implication in repetitive mild traumatic brain injury remains uncharted. To address this gap, we characterized the spatial distribution of metal levels (iron, zinc, and copper) using laser ablation-inductively coupled plasma-mass spectrometry, the profile of metal-binding proteins via size exclusion chromatography-inductively coupled plasma-mass spectrometry and the expression of the major iron storing protein ferritin via western blotting. Using a mouse model of repetitive mild traumatic brain injury, 3-month-old male and female C57Bl6 mice received one or five impacts (48h apart). At 1 month following 5× TBI (traumatic brain injury), iron and ferritin levels were significantly elevated in the contralateral cortex. There was a trend toward increased iron levels in the entire contralateral hemisphere and a reduction in contralateral cortical iron-binding proteins following 1× TBI. No major changes in zinc levels were seen in both hemispheres following 5× or 1× TBI, although there was a reduction in ipsilateral zinc-binding proteins following 5× TBI and a contralateral increase in zinc-binding proteins following 1× TBI. Copper levels were significantly increased in both hemispheres following 5× TBI, without changes in copper-binding proteins. This study shows for the first time that repetitive mild TBI (r-mTBI) leads to metal dyshomeostasis, highlighting its potential involvement in promoting neurodegeneration, which provides a rationale for examining the benefit of metal-targeting drugs, which have shown promising results in neurodegenerative conditions and single TBI, but have yet to be tested following r-mTBI.

Field Reflectance Measurements at Night of Beach and Desert Sands within a Particulate BRDF Model

The Bidirectional Reflectance Distribution Function (BRDF) of soils is frequently assumed to be Lambertian in remote sensing applications, even though many soils are observed to have a distinct backscatter. This is largely due to the difficulty of obtaining accurate in-situ BRDF of these materials over the entire hemisphere. The objective of the work presented here is to describe a new technique that combines the measurement of field BRDF data on desert and beach sands measured at night with a model that reproduces the backscatter except in a small region around zero phase angle. It is found that this combination produces parameterized BRDF of sufficient accuracy to allow its inclusion in a remote sensing materials database. The measurement technique was developed in the laboratory and transitioned to perform in-plane BRDF field measurements of sands at night. Field measurements were obtained using a portable light source and field spectrometer over the range of 0.4–2.4 micrometers. The spectrometer sensor optics and light source were mounted on a portable, manually operated goniometer allowing in-plane measurements to within 3 degrees of backscatter. Unlike daytime measurements, corrections for background were unnecessary, and BRDF was obtained by referencing to a Spectralon calibration standard. Analysis of the spectrometer field data used a variant of the Shadow Hiding Opposition Effect (SHOE) wherein a series expansion of Legendre Polynomials was substituted for the angularly dependent backscatter function. It is shown that when the out-of-plane scattering and the backscatter peak are small, this model provides an adequate description of the BRDF. The combination of the nocturnal in-situ measurements with an analysis using a model that can describe the backscatter produces parameterized BRDF for these sands of sufficient accuracy to allow inclusion in the NEFDS materials database. Measurement and analysis techniques are assessed, sample results for both the laboratory and field data are shown, and the extension to future soils measurements are discussed.

Large-scale waves of activity in the neonatal mouse brain in vivo occur almost exclusively during sleep cycles.

Spontaneous electrical activity plays major roles in the development of cortical circuitry. This activity can occur highly localized regions or can propagate over the entire cortex. Both types of activity coexist during early development. To investigate how different forms of spontaneous activity might be temporally segregated, we used wide-field trans-cranial calcium imaging over an entire hemisphere in P1-P8 mouse pups. We found that spontaneous waves of activity that propagate to cover the majority of the cortex (large-scale waves; LSWs) are generated at the end of the first postnatal week, along with several other forms of more localized activity. We further found that LSWs are segregated into sleep cycles. In contrast, cortical activity during wake states is more spatially restricted and the few large-scale forms of activity that occur during wake can be distinguished from LSWs in sleep based on their initiation in the motor cortex and their correlation with body movements. This change in functional cortical circuitry to a state that is permissive for large-scale activity may temporally segregate different forms of activity during critical stages when activity-dependent circuit development occurs over many spatial scales. Our data also suggest that LSWs in early development may be a functional precursor to slow sleep waves in the adult, which play critical roles in memory consolidation and synaptic rescaling.

An alternative to Hapke’s macroscopic roughness correction

In this paper, we present an alternative to Hapke’s correction for the photometric effect of macroscopic roughness of planetary surfaces (Hapke, 1984). Our model includes the effects of both single-facet scattering and multi-facet scattering. The single-facet scattering model is derived directly from the definition of bidirectional reflectance of a rough surface. We model projected shadowing by adopting an approximation published elsewhere in the literature. Monte Carlo simulations of single-facet scattering demonstrate very good agreement with the single-facet scattering component of our model. Using 3D printed molds with known roughness statistics, we prepared rough mineral surfaces consisting of quartz and olivine in the laboratory. We recorded extensive measurements of the rough surface bidirectional reflectance over a wide range of illumination and view geometries at 1751 wavelength bands ranging from 500–2250 nm. By fitting the residual between the measured bidirectional reflectance and our single-facet scattering model, we developed an empirical approximation for multi-facet scattering. Our results show that the multi-facet scattering is proportional to the surface’s diffusive reflectance, RMS slope, and the cosine of the illumination angle. Furthermore, the multi-facet scattering is approximately Lambertian for phase angles less than 90° but becomes forward scattering at higher phase angles. Our empirical multi-facet scattering model incorporates all of these features. As a surface becomes more macroscopically rough, our data show that the overall reflectance distribution becomes progressively more backscattering in a way that is distinct from the shadow hiding opposition effect. We refer to this effect as the macroscopic roughness backscattering bias (MRBB), which affects the entire hemisphere rather than being localized to small phase angles. Our proposed model is more accurate than Hapke’s for phase angles less than 90°, and the accuracy of the two models is comparable at higher phase angles. However, researchers should be aware of an issue regarding the roughness parameter defined in Hapke’s model, namely the fact that “ϑ¯” is not actually equal to the mean slope angle of the surface for the probability density function used in the model. This is an issue which apparently has gone unnoticed in the literature, and has potentially caused the model to be applied incorrectly in past studies.

Health Status of Bycaught Common Eiders (Somateria mollissima) from the Western Baltic Sea.

Simple SummaryWe performed post-mortem investigations of 121 Common Eiders (Somateria mollissima), which were incidentally caught in fishing gear from 2017 to 2019 in Denmark. The aim of the study was to obtain an overview of health issues and pathogens occurring in the population of these birds. The European population of the Common Eider is endangered, but the reasons for the decline of the population have not yet been determined. In times of accelerating species loss, it is important to determine factors that impact population numbers of declining species. The post-mortem investigations included biometric measurements and determination of age, sex and nutritional status, as well as parasitological, bacteriological and virological investigations. The majority of Common Eiders had a good or moderate nutritional status. Most animals were infected with intestinal parasites, and we commonly found inflammation in organs like the liver, kidneys, intestine and the oesophagus. In three animals, a pathogenic bacterium caused inflammatory lesions in several organs. We did not find signs for epizootic diseases or pathologies, which would explain the declining species numbers. The Common Eider (Somateria mollissima) inhabits the entire northern hemisphere. In northern Europe, the flyway population reaches from the southern Wadden Sea to the northern Baltic coast. The European population is classified as endangered due to declines in Common Eider numbers across Europe since 1990. In this study, we assessed 121 carcasses of Common Eiders, captured incidentally in gillnets in the Western Baltic between 2017 and 2019. The most common findings were parasitic infections of the intestine by acanthocephalans in 95 animals, which correlated with enteritis in 50% of the cases. Parasites were identified as Profilicollis botulus in 25 selected animals. Additionally, oesophageal pustules, erosions, and ulcerations, presumably of traumatic origin, were frequently observed. Nephritis and hepatitis were frequent, but could not be attributed to specific causes. Lung oedema, fractures and subcutaneous haemorrhages likely resulted from entangling and drowning. Two Common Eiders had mycobacterial infections and in one of these, Mycobacterium avium subspecies (ssp.) avium was identified. This study gives an overview of morphological changes and infectious diseases from one location of the European flyway population. It contributes to future health studies on Common Eiders in the Baltic and Wadden Seas by providing baseline information to compare with other areas or circumstances.

In Vivo Wide-Field and Two-Photon Calcium Imaging from a Mouse using a Large Cranial Window.

Wide-field calcium imaging from the mouse's neocortex allows one to observe cortex-wide neural activity related to various brain functions. On the other hand, two-photon imaging can resolve the activity of local neural circuits at the single-cell level. It is critical to make a large cranial window to perform multiple-scale analysis using both imaging techniques in the same mouse. To achieve this, one must remove a large section of the skull and cover the exposed cortical surface with transparent materials. Previously, glass skulls and polymer-based cranial windows have been developed for this purpose, but these materials are not easily fabricated. The present protocol describes a simple method for making a large cranial window consisting of commercially available polyvinylidene chloride (PVDC) wrapping film, a transparent silicone plug, and a cover glass. For imaging the dorsal surface of an entire hemisphere, the window size was approximately 6 x 3 mm2. Severe brain vibrations were not observed regardless of such a large window. Importantly, the condition of the brain surface did not deteriorate for more than one month. Wide-field imaging of a mouse expressing a genetically-encoded calcium indicator (GECI), GCaMP6f, specifically in astrocytes, revealed synchronized responses in a few millimeters. Two-photon imaging of the same mouse showed prominent calcium responses in individual astrocytes over several seconds. Furthermore, a thin layer of an adeno-associated virus was applied to the PVDC film and successfully expressed GECI in cortical neurons over the cranial window. This technique is reliable and cost-effective for making a large cranial window and facilitates the investigation of the neural and glial dynamics and their interactions during behavior at the macroscopic and microscopic levels.

&lt;em&gt;In Vivo&lt;/em&gt; Wide-Field and Two-Photon Calcium Imaging from a Mouse Using a Large Cranial Window

Wide-field calcium imaging from the mouse's neocortex allows one to observe cortex-wide neural activity related to various brain functions. On the other hand, two-photon imaging can resolve the activity of local neural circuits at the single-cell level. It is critical to make a large cranial window to perform multiple-scale analysis using both imaging techniques in the same mouse. To achieve this, one must remove a large section of the skull and cover the exposed cortical surface with transparent materials. Previously, glass skulls and polymer-based cranial windows have been developed for this purpose, but these materials are not easily fabricated. The present protocol describes a simple method for making a large cranial window consisting of commercially available polyvinylidene chloride (PVDC) wrapping film, a transparent silicone plug, and a cover glass. For imaging the dorsal surface of an entire hemisphere, the window size was approximately 6 x 3 mm2. Severe brain vibrations were not observed regardless of such a large window. Importantly, the condition of the brain surface did not deteriorate for more than one month. Wide-field imaging of a mouse expressing a genetically-encoded calcium indicator (GECI), GCaMP6f, specifically in astrocytes, revealed synchronized responses in a few millimeters. Two-photon imaging of the same mouse showed prominent calcium responses in individual astrocytes over several seconds. Furthermore, a thin layer of an adeno-associated virus was applied to the PVDC film and successfully expressed GECI in cortical neurons over the cranial window. This technique is reliable and cost-effective for making a large cranial window and facilitates the investigation of the neural and glial dynamics and their interactions during behavior at the macroscopic and microscopic levels.