Hemisphere Regions Research Articles

Snow Depth Fusion Based on Machine Learning Methods for the Northern Hemisphere

In this study, a machine learning algorithm was introduced to fuse gridded snow depth datasets. The input variables of the machine learning method included geolocation (latitude and longitude), topographic data (elevation), gridded snow depth datasets and in situ observations. A total of 29,565 in situ observations were used to train and optimize the machine learning algorithm. A total of five gridded snow depth datasets—Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) snow depth, Global Snow Monitoring for Climate Research (GlobSnow) snow depth, Long time series of daily snow depth over the Northern Hemisphere (NHSD) snow depth, ERA-Interim snow depth and Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2) snow depth—were used as input variables. The first three snow depth datasets are retrieved from passive microwave brightness temperature or assimilation with in situ observations, while the last two are snow depth datasets obtained from meteorological reanalysis data with a land surface model and data assimilation system. Then, three machine learning methods, i.e., Artificial Neural Networks (ANN), Support Vector Regression (SVR), and Random Forest Regression (RFR), were used to produce a fused snow depth dataset from 2002 to 2004. The RFR model performed best and was thus used to produce a new snow depth product from the fusion of the five snow depth datasets and auxiliary data over the Northern Hemisphere from 2002 to 2011. The fused snow-depth product was verified at five well-known snow observation sites. The R2 of Sodankylä, Old Aspen, and Reynolds Mountains East were 0.88, 0.69, and 0.63, respectively. At the Swamp Angel Study Plot and Weissfluhjoch observation sites, which have an average snow depth exceeding 200 cm, the fused snow depth did not perform well. The spatial patterns of the average snow depth were analyzed seasonally, and the average snow depths of autumn, winter, and spring were 5.7, 25.8, and 21.5 cm, respectively. In the future, random forest regression will be used to produce a long time series of a fused snow depth dataset over the Northern Hemisphere or other specific regions.

Computational support, not primacy, distinguishes compensatory memory reorganization in epilepsy.

Temporal lobe epilepsy is associated with impairment in episodic memory. A substantial subgroup, however, is able to maintain adequate memory despite temporal lobe pathology. Missing from prior work in cognitive reorganization is a direct comparison of temporal lobe epilepsy patients with intact status with those who are memory impaired. Little is known about the regional activations, functional connectivities and/or network reconfigurations that implement changes in primary computations or support functions that drive adaptive plasticity and compensated memory. We utilized task functional MRI on 54 unilateral temporal lobe epilepsy patients and 24 matched healthy controls during the performance of a paired-associate memory task to address three questions: (i) which regions implement paired-associate memory in temporal lobe epilepsy, and do they vary as a function of good versus poor performance, (ii) is there unique functional connectivity present during memory encoding that accounts for intact status by preservation of primary memory computations or the supportive computations that allow for intact memory responses and (iii) what features during memory encoding are most distinctive: is it the magnitude and location of regional activations, or the presence of enhanced functional connections to key structures such as the hippocampus? The study revealed non-dominant hemisphere regions (right posterior temporal regions) involving both increased regional activity and increased modulatory communication with the hippocampi as most important to intact memory in left temporal lobe epilepsy compared to impaired status. The profile involved areas that are neither contralateral homologues to left hemisphere memory areas, nor regions traditionally considered computationally primary for episodic memory. None of these areas of increased activation or functional connectivity were associated with advantaged memory in healthy controls. Our emphasis on different performance levels yielded insight into two forms of cognitive reorganization: computational primacy, where left temporal lobe epilepsy showed little change relative to healthy controls, and computational support where intact left temporal lobe epilepsy patients showed adaptive abnormalities. The analyses isolated the unique regional activations and mediating functional connectivity that implements truly compensatory reorganization in left temporal lobe epilepsy. The results provided a new perspective on memory deficits by making clear that they arise not just from the knockout of a functional hub, but from the failure to instantiate a complex set of reorganization responses. Such responses provided the computational support to ensure successful memory. We demonstrated that by keeping track of performance levels, we can increase understanding of adaptive brain responses and neuroplasticity in epilepsy.

Jassa (Crustacea: Amphipoda): a new morphological and molecular assessment of the genus.

The amphipod genus Jassa Leach, 1814 now comprises 24 species that occur in temperate regions of both hemispheres on solid substrates from the lower intertidal zone to 500 m depth. The propensity for some species to form dense colonies in water intake structures and offshore platforms has brought them to attention as an unwanted pest. Based on the examination of ~25,000 specimens from ~1,100 museum and private collections, it is evident that some species of Jassa have been transported by human vectors since at least the 19th century and now occur widely. Their colonial, tube-living habit enables such transport, and collection records document them on ships, buoys and portable water systems as well as on natural movable substrates such as logs, drift algae and larger crustaceans. Because Jassa can be so readily found, but species discrimination has had a problematic history, the purpose of this monograph is to assist researchers to identify species through illustrations, descriptions, keys and habitat summaries. Seven species which were named in the 19th century but whose names have lapsed are placed in the context of currently known species. Two new species, J. laurieae n. sp. and J. kimi n. sp. are described, and J. monodon (Heller, 1866) and J. valida (Dana, 1853) are resurrected. Jassa mendozai Winfield et al., 2021 is submerged under J. valida, and J. cadetta Krapp et al., 2008 and J. trinacriae Krapp et al., 2010 are submerged under J. slatteryi Conlan, 1990. Morphological differences are related to current understanding of growth, behaviour and ecology. CO1 analysis suggests a Southern Hemisphere origin with diversification northward and an evolutionary direction toward greater physiological plasticity, leading to success in long distance transport and establishment in exotic locations. Correct identification of Jassa world-wide will facilitate further research on this ecologically important genus and will allow for differentiation of indigenous from exotic introductions.

EEG Feature Extraction Based on Brain Function Network and Sample Entropy

For the low recognition rate of motor imagery ElectroEncephaloGram (EEG) signals using single feature in Brain-Computer Interface (BCI) research, a feature extraction method combining brain function network and sample entropy is proposed. According to the neural mechanism appearing in Event Related Synchronization/Event Related Desynchronization (ERS/ERD) phenomenon and the contralateral mapping mechanism between cortex and limb motor imagery, the μ rhythm is denoised by wavelet packet transform. The brain function network is constructed for left hemispherical brain region and right hemispherical brain region by μ rhythm of 27 left channels and 27 right channels respectively. The mean node degree and the mean clustering coefficient are calculated as the brain function network characteristics, and the feature vectors combining the distribution and directivity are constructed by the sample entropy of C3 and C4 channels with the μ rhythm. The Support Vector Machine (SVM) is used to classify the left hand and right hand motor imagery EEG signals. The results show that the feature extraction method based on brain function network and sample entropy achieves better classification result, and the highest classification rate reached 90.27%.

Can quantifying morphology and TMEM119 expression distinguish between microglia and infiltrating macrophages after ischemic stroke and reperfusion in male and female mice?

BackgroundIschemic stroke is an acquired brain injury with gender-dependent outcomes. A persistent obstacle in understanding the sex-specific neuroinflammatory contributions to ischemic brain injury is distinguishing between resident microglia and infiltrating macrophages—both phagocytes—and determining cell population-specific contributions to injury evolution and recovery processes. Our purpose was to identify microglial and macrophage populations regulated by ischemic stroke using morphology analysis and the presence of microglia transmembrane protein 119 (TMEM119). Second, we examined sex and menopause differences in microglia/macrophage cell populations after an ischemic stroke.MethodsMale and female, premenopausal and postmenopausal, mice underwent either 60 min of middle cerebral artery occlusion and 24 h of reperfusion or sham surgery. The accelerated ovarian failure model was used to model postmenopause. Brain tissue was collected to quantify the infarct area and for immunohistochemistry and western blot methods. Ionized calcium-binding adapter molecule, TMEM119, and confocal microscopy were used to analyze the microglia morphology and TMEM119 area in the ipsilateral brain regions. Western blot was used to quantify protein quantity.ResultsPost-stroke injury is increased in male and postmenopause female mice vs. premenopause female mice (p < 0.05) with differences primarily occurring in the caudal sections. After stroke, the microglia underwent a region, but not sex group, dependent transformation into less ramified cells (p < 0.0001). However, the number of phagocytic microglia was increased in distal ipsilateral regions of postmenopausal mice vs. the other sex groups (p < 0.05). The number of TMEM119-positive cells was decreased in proximity to the infarct (p < 0.0001) but without a sex group effect. Two key findings prevented distinguishing microglia from systemic macrophages. First, morphological data were not congruent with TMEM119 immunofluorescence data. Cells with severely decreased TMEM119 immunofluorescence were ramified, a distinguishing microglia characteristic. Second, whereas the TMEM119 immunofluorescence area decreased in proximity to the infarcted area, the TMEM119 protein quantity was unchanged in the ipsilateral hemisphere regions using western blot methods.ConclusionsOur findings suggest that TMEM119 is not a stable microglia marker in male and female mice in the context of ischemic stroke. Until TMEM119 function in the brain is elucidated, its use to distinguish between cell populations following brain injury with cell infiltration is cautioned.

Parcellation-based anatomic model of the semantic network.

IntroductionThe semantic network is an important mediator of language, enabling both speech production and the comprehension of multimodal stimuli. A major challenge in the field of neurosurgery is preventing semantic deficits. Multiple cortical areas have been linked to semantic processing, though knowledge of network connectivity has lacked anatomic specificity. Using attentional task‐based fMRI studies, we built a neuroanatomical model of this network.MethodsOne hundred and fifty‐five task‐based fMRI studies related to categorization of visual words and objects, and auditory words and stories were used to generate an activation likelihood estimation (ALE). Cortical parcellations overlapping the ALE were used to construct a preliminary model of the semantic network based on the cortical parcellation scheme previously published under the Human Connectome Project. Deterministic fiber tractography was performed on 25 randomly chosen subjects from the Human Connectome Project, to determine the connectivity of the cortical parcellations comprising the network.ResultsThe ALE analysis demonstrated fourteen left hemisphere cortical regions to be a part of the semantic network: 44, 45, 55b, IFJa, 8C, p32pr, SFL, SCEF, 8BM, STSdp, STSvp, TE1p, PHT, and PBelt. These regions showed consistent interconnections between parcellations. Notably, the anterior temporal pole, a region often implicated in semantic function, was absent from our model.ConclusionsWe describe a preliminary cortical model for the underlying structural connectivity of the semantic network. Future studies will further characterize the neurotractographic details of the semantic network in the context of medical application.

The Role of the Right Hemisphere in Processing Phonetic Variability Between Talkers.

Neurobiological models of speech perception posit that both left and right posterior temporal brain regions are involved in the early auditory analysis of speech sounds. However, frank deficits in speech perception are not readily observed in individuals with right hemisphere damage. Instead, damage to the right hemisphere is often associated with impairments in vocal identity processing. Herein lies an apparent paradox: The mapping between acoustics and speech sound categories can vary substantially across talkers, so why might right hemisphere damage selectively impair vocal identity processing without obvious effects on speech perception? In this review, I attempt to clarify the role of the right hemisphere in speech perception through a careful consideration of its role in processing vocal identity. I review evidence showing that right posterior superior temporal, right anterior superior temporal, and right inferior / middle frontal regions all play distinct roles in vocal identity processing. In considering the implications of these findings for neurobiological accounts of speech perception, I argue that the recruitment of right posterior superior temporal cortex during speech perception may specifically reflect the process of conditioning phonetic identity on talker information. I suggest that the relative lack of involvement of other right hemisphere regions in speech perception may be because speech perception does not necessarily place a high burden on talker processing systems, and I argue that the extant literature hints at potential subclinical impairments in the speech perception abilities of individuals with right hemisphere damage.

Sensory acquisition functions of the cerebellum in verbal working memory

Several fMRI studies have shown that the superior cerebellum exhibits load-dependent activations during encoding of letters in a Sternberg verbal working memory (VWM) task. It has been hypothesized that the cerebellum regulates the acquisition of sensory data across all modalities, and thus, that VWM load activations may reflect high- vs low-load differences in sensory acquisition demands. Therefore, increased difficulty in sensory data acquisition should elicit greater activation in the cerebellum. The present fMRI study manipulated sensory acquisition in VWM by presenting visually degraded and non-degraded stimuli with high and low memory loads, thereby identifying load-dependent regions of interest in the cerebellum, and then testing if these regions showed greater activation for degraded stimuli. Results yielded partial support for the sensory acquisition hypothesis in a load-dependent region of the vermis, which showed significantly greater activation for degraded relative to non-degraded stimuli. Because eye movements did not differ for these stimulus types, and degradation-related activations were present after co-varying eye movements, this activation appears to be related to perceptual rather than oculomotor demands. In contrast to the vermis, load-sensitive regions of the cerebellar hemispheres did not show increased activation for degraded stimuli. These findings point to an overall function of association-based prediction that may underlie general cerebellar function, with perceptual prediction of stimuli from partial representations occurring in the vermis, and articulatory prediction occurring in the hemispheres.

Semi-Automated Cell and Tissue Analyses Reveal Regionally Specific Morphological Alterations of Immune and Neural Cells in a Porcine Middle Cerebral Artery Occlusion Model of Stroke.

Histopathological analysis of cellular changes in the stroked brain provides critical information pertaining to inflammation, cell death, glial scarring, and other dynamic injury and recovery responses. However, commonly used manual approaches are hindered by limitations in speed, accuracy, bias, and the breadth of morphological information that can be obtained. Here, a semi-automated high-content imaging (HCI) and CellProfiler histological analysis method was developed and used in a Yucatan miniature pig permanent middle cerebral artery occlusion (pMCAO) model of ischemic stroke to overcome these limitations. Evaluation of 19 morphological parameters in IBA1+ microglia/macrophages, GFAP+ astrocytes, NeuN+ neuronal, FactorVIII+ vascular endothelial, and DCX+ neuroblast cell areas was conducted on porcine brain tissue 4 weeks post pMCAO. Out of 19 morphological parameters assessed in the stroke perilesional and ipsilateral hemisphere regions (38 parameters), a significant change in measured IBA1+ parameters, GFAP+ parameters, NeuN+ parameters, FactorVIII+ parameters, and DCX+ parameters were observed in stroked vs. non-stroked animals. Principal component analysis (PCA) and correlation analyses demonstrated that stroke-induced significant and predictable morphological changes that demonstrated strong relationships between IBA1+, GFAP+, and NeuN+ areas. Ultimately, this unbiased, semi-automated HCI and CellProfiler histopathological analysis approach revealed regional and cell specific morphological signatures of immune and neural cells after stroke in a highly translational porcine model. These identified features can provide information of disease pathogenesis and evolution with high resolution, as well as be used in therapeutic screening applications.

Parcellation-based modeling of the supplementary motor area

IntroductionThe supplementary motor area (SMA) plays an important role in the initiation and coordination of internally and externally cued movements. Such movements include reaching, grasping, speaking, and bilateral hand coordination. While many studies discuss the SMA and its relationship to other parts of the motor network, there is minimal literature examining the connectivity of the SMA outside of the motor network. Using region-based fMRI studies, we built a neuroanatomical model to account for these extra-motor connections. MethodsThirty region-based fMRI studies were used to generate an activation likelihood estimation (ALE) using BrainMap software. Cortical parcellations overlapping the ALE were used to construct a preliminary model of the SMA connections outside the motor network. DSI-based fiber tractography was performed to determine the connectivity between cortical parcellations. The resulting connections were described using the cortical parcellation scheme developed by the Human Connectome Project (HCP). ResultsFour left hemisphere regions were found to comprise the SMA. These included areas SFL, SCEF, 6ma, and 6mp. Across mapped brains, these areas showed consistent interconnections between each other. Additionally, ipsilateral connections to the primary motor cortex, left inferior and middle frontal gyri, the anterior cingulate gyrus, and insula were demonstrated. Connections to the contralateral SMA, anterior cingulate, lateral premotor, and inferior frontal cortices were also identified. ConclusionsWe describe a preliminary cortical model for the underlying structural connectivity of the supplementary motor area outside the motor network. Future studies should further characterize the neuroanatomic underpinnings of this network for the purposes of medical application.

Resting-state EEG alpha/theta ratio related to neuropsychological test performance in Parkinson’s Disease

ObjectiveTo determine possible associations of hemispheric-regional alpha/theta ratio (α/θ) with neuropsychological test performance in Parkinson’s Disease (PD) non-demented patients. Methods36 PD were matched to 36 Healthy Controls (HC). The α/θ in eight hemispheric regions was computed from the relative power spectral density of the resting-state quantitative electroencephalogram (qEEG). Correlations between α/θ and performance in several neuropsychological tests were conducted, significant findings were included in a moderation analysis. ResultsThe α/θ in all regions was lower in PD than in HC, with larger effect sizes in the posterior regions. Right parietal, and right and left occipital α/θ had significant positive correlations with performance in Judgement of Line Orientation Test (JLOT) in PD. Adjusted moderation analysis indicated that right, but not left, occipital α/θ influenced the JLOT performance related to PD. ConclusionsReduction of the occipital α/θ, in particular on the right side, was associated with visuospatial performance impairment in PD. SignificanceVisuospatial impairment in PD, which is highly correlated with the subsequent development of dementia, is reflected in α/θ in the right posterior regions. The right occipital α/θ may represent a useful qEEG marker for evaluating the presence of early signs of cognitive decline in PD and the subsequent risk of dementia.

Evolution of litter size in bats and its influence on longevity and roosting ecology

Abstract Litter size varies in mammals, with about half of the species producing at least two offspring per gestation (polytocy). In bats, however, the modal litter size is one (monotocy), and polytocy is restricted to family Vespertilionidae. Here, we reconstruct the evolutionary history of polytocy in chiropterans and use phylogenetically informed regressions to investigate its relationship to roost type, longevity and group size. Our phylogenetic reconstructions suggested that production of multiple offspring was the ancestral condition in family Vespertilionidae. The distribution of monotocy/polytocy in Chiroptera was best explained by a minimum of two evolutionary transitions from monotocy to polytocy and by ≥ 18 transitions from polytocy to monotocy. The regression models showed that longevity and roost type explained the variation in litter size, whereas group size did not. Our analyses also revealed a greater diversity of polytocous bats in the Northern Hemisphere, in both temperate and tropical regions. We suggest that the high resource allocation to reproduction in polytocous bats limited their lifespan. The absence of a relationship between polytocy and group size indicates that the benefits of cooperative breeding surpass the costs of intrasexual competition in bats.

A window to the world of global insect declines: Moth biodiversity trends are complex and heterogeneous

Moths are the most taxonomically and ecologically diverse insect taxon for which there exist considerable time-series abundance data. There is an alarming record of decreases in moth abundance and diversity from across Europe, with rates varying markedly among and within regions. Recent reports from Costa Rica reveal steep cross-lineage declines of caterpillars, while other sites (Ecuador and Arizona, reported here) show no or only modest long-term decreases over the past two decades. Rates of decline for dietary and ecological specialists are steeper than those for ecologically generalized taxa. Additional traits commonly associated with elevated risks include large wingspans, small geographic ranges, low dispersal ability, and univoltinism; taxa associated with grasslands, aridlands, and nutrient-poor habitats also appear to be at higher risk. In temperate areas, many moth taxa limited historically by abiotic factors are increasing in abundance and range. We regard the most important continental-scale stressors to include reductions in habitat quality and quantity resulting from land-use change and climate change and, to a lesser extent, atmospheric nitrification and introduced species. Site-specific stressors include pesticide use and light pollution. Our assessment of global macrolepidopteran population trends includes numerous cases of both region-wide and local losses and studies that report no declines. Spatial variation of reported losses suggests that multiple stressors are in play. With the exception of recent reports from Costa Rica, the most severe examples of moth declines are from Northern Hemisphere regions of high human-population density and intensive agriculture.

An inverse relationship between South China Sea summer monsoon intensity and ENSO

Correlations between the South China Sea summer (June-September) monsoon (SCSSM) and El Niño Southern Oscillation (ENSO) for the past 32 years (1979–2010) were analyzed. As a result, a higher (lower) SST in the Niño-3.4 areas was associated with a weaker (stronger) SCSSM intensity. To examine the cause of this correlation, the differences between the June-September average of 8 El Niño years and the June-September average of 8 La Niña years were analyzed. Differences in the 850 hPa stream flows between the two groups found that anomalous huge cyclones existed in the subtropical Pacific regions of both hemispheres, which reinforced cold and dry anomalous northerlies in the SCS and anomalous westerlies from the Maritime Continent (MC) to the coastal waters of Chile. An analysis of the differences in the 200 hPa stream flows between the two groups found an anomalous pressure system pattern that was opposite to the result of the analysis of the differences in the 850 hPa stream flows between the two groups. Anomalous anticyclones existed in the subtropical Pacific of both hemispheres, which reinforced the anomalous easterlies from the MC to the equatorial central Pacific. When the anomalous atmospheric circulations of the upper and lower layers of the troposphere were also considered, the structure of anomalous atmospheric circulations in which the air current that rose in the equatorial central and eastern Pacific fell down in the MC. This indicates weakening of the Walker Circulation and a typical structure of atmospheric circulations that appears in El Niño years.

Malpighiaceae de Colombia: Patrones de distribución, riqueza, endemismo y diversidad filogenética

Malpighiaceae constitutes a family of 77 genera and ca. 1300 species, distributed in tropical and subtropical regions of both hemispheres. They are mainly diversified in the American continent and distributed in a wide range of habitats and altitudinal gradients. For this reason, this family can be a model plant group to ecological and biogeographical analyses, as well as evolutive studies. In this context, an analysis of distribution, richness, endemism and phylogenetic diversity of Malpighiaceae in natural regions and their altitudinal gradients was undertaken. Malpighiaceae are represented in Colombia by 34 genera and 246 species (19.1% of endemism). Thus, Colombia and Brazil (44 genera, 584 species, 61% of endemism) are the two richest countries on species of this family. The highest species richness and endemism in Colombia is found in the lowlands (0-500 m a.s.l.: 212 species, 28 endemics); only ten species are distributed on highlands (2500-3200 m a.s.l.). Of the Malpighiaceae species in Colombia, Heteropterys leona and Stigmaphyllon bannisterioides have a disjunct amphi-Atlantic distribution, and six other species show intra-American disjunctions. Both richness and endemism decrease with altitude (y = -0.061x + 173.57; R2 = 0.82; y = -0.009x + 27.76; R2 = 0.95, respectively). Amazonia (116 species, 4 endemics) and the Andes (89 species, 23 endemics) exhibit the highest richness among the family. In Colombia, 15 of the 19 clades among the family are represented, where the most diversified are the Stigmaphyllon clade (5 genera, 48 species, 10 endemics), the Byrsonima clade (3/39/5) and the Hiraea clade (3/31/9). The relationship of phylogenetic diversity with altitude is similar to the pattern of specific richness by altitudinal interval. Amazonia, Orinoquia, and Magdalena Valley show highest phylogenetic diversity. These results, combined with those of other highly diversified biological groups in the country, could be important to define and delimitate new priority areas for conservation in Colombia.

Morfología comparada de diez taxones del género Celtis (Cannabaceae) del Cono Sur Sudamericano

The genus Celtis L. (Cannabaceae) comprises around 73 species distributed in temperate and tropical regions of both hemispheres. Most South American species belong to the subgenus Mertensia Planch., and they are characterized by showing high morphological plasticity. A recent taxonomic revision of this group was carried out with an excessively reductionist criterion regarding the number of accepted species and that does not clearly reflect the morphological differences among them. In order to contribute to the correct delimitation of the specific entities, a morpho-descriptive approach is presented for ten taxa of the genus Celtis (C. brasiliensis, C. chichape, C. clausseniana, C. fluminensis, C. pallida var. pallida, C pallida var. discolor, C. serratissima, C. spinosa, C. spinosissima and C. tala) growing in South American Southern Cone. The morphology was analyzed through the use of a stereomicroscope and/or the tpsDig program for digital images of specimens. As a result, a key is provided for the determination of the aforementioned species and a detailed morphological description of the vegetative (habit, bark, branches, spines, brachyblasts, indumentum and leaves) and reproductive structures (inflorescences, flowers, fruits and endocarp -pyrene-). In addition, a specimen collection guide is proposed with a list of the main morphological characters that should be observed in the field, to facilitate future identifications.

Morphological and molecular characters of Scutellonema brachyurus () from South Africa.

During a survey on plant-parasitic nematodes from South Africa, Scutellonema brachyurus was recovered from soil samples collected around the rhizosphere of wild grass in the North West and Limpopo provinces. This species characterized by a hemispherical lip region with four to six annuli, basal lip’s annuli with longitudinal incisures, body length 696–904 µm (a = 25.1–33.5; b = 5.0–7.2; c = 48.9–75.3; c’ = 0.5–0.9; V = 55–60), stylet 21–27 µm length, tail rounded with 10–19 µm length and spermatheca nonfunctional and male absent. The nblast analysis based on the D2-D3 segment of 28 S rDNA placed South African populations of S. brachyurus with 98% similarity to Greece (KU059494) and 99% similarity to South African (JX472052) S. brachyurus. Besides, nblast of COI of mtDNA showed 98% similarity of the test species with South African populations of S. brachyurus (JX472096; JX472097). The phylogenetic analysis put the South African populations of S. brachyurus together with other S. brachyurus with a 100 posterior probability support. Besides, the measurements, line illustration, and scanning electron microscopy photographs are provided for S. brachyurus from South Africa.

Ionospheric Diurnal Double‐Maxima Patterns Observed by the TEC From Beidou Geostationary Satellites in the Asian‐Australian Sector During 2016–2018

AbstractStatistical analysis was conducted to investigate the ionospheric diurnal double‐maxima (DDM) patterns using the total electron content (TEC) from the Beidou geostationary (GEO) satellites. The data were used over the Asian‐Australian sector during 2016–2018. It was found that the ionospheric DDM had the obvious seasonal and latitudinal variations as well as hemispheric differences. The occurrence rate of ionospheric DDM presented a semi‐annual variation with a main peak around the June solstice (local summer) and a secondary peak around the December solstice in the northern hemisphere and equator region, whereas an annual variation with the highest occurrence rate around the June solstice (local winter) was observed in the southern hemisphere. Furthermore, the occurrence rate of ionospheric DDM around the equatorial ionization anomaly crest region was lower than that at other latitudes. There was an anti‐correlation between the occurrence rate of ionospheric DDM and the background TEC, indicating that the drivers, which determine the variations of the background TEC, possibly play an important role in producing the latitudinal and seasonal variations of ionospheric DDM as well. Nevertheless, the causative mechanisms could be different for daytime and post‐sunset DDMs.

Analytical Study of Severe and Great Geomagnetic Storms

Severe and Great Geomagnetic storms are considered to be those which have Dst less than -200nT. The investigation years are January 1996 to December 2006, which refers to 23rd solar cycle. During this period, 18 Geomagnetic storms are observed. When there are maximum number of sunspots present at the solar disk, highest number of these Geomagnetic storms are observed, which is quite obvious. The Coronal Mass Ejections responsible for these storms depict latitudinal as well as longitudinal bias showing more inclination towards northern hemisphere and western region of the solar disk. These Coronal Mass Ejections are confined between 25 of the equator.

Discriminatory experiences predict neuroanatomical changes and anxiety among healthy individuals and those at clinical high risk for psychosis

Individuals face discrimination based on characteristics including race/ethnicity, gender, age, and disability. Discriminatory experiences (DE) are associated with poor psychological health in the general population and with worse outcomes among individuals at clinical high risk for psychosis (CHR). Though the brain is sensitive to stress, and brain structural change is a well-documented precursor to psychosis, potential relationships between DE and brain structure among CHR or healthy individuals are not known. This report assessed whether lifetime DE are associated with cortical thinning and clinical outcomes across time, after controlling for discrimination-related demographic factors among CHR individuals who ultimately do (N = 57) and do not convert to psychosis (N = 451), and healthy comparison (N = 208) participants in the North American Prodrome Longitudinal Study 2. Results indicate that DE are associated with thinner cortex across time in several cortical areas. Thickness in several right hemisphere regions partially mediates associations between DE and subsequent anxiety symptoms, but not attenuated positive symptoms of psychosis. This report provides the first evidence to date of an association between DE and brain structure in both CHR and healthy comparison individuals. Results also suggest that thinner cortex across time in areas linked with DE may partially explain associations between DE and cross-diagnostic indicators of psychological distress.