Hemispheric Localization Research Articles

Возрастные и половые различия структурно-функционального состояния сердца у пациентов с церебральным атеросклерозом и сахарным диабетом

Цереброваскулярные заболевания — одна из важнейших причин заболеваемости и смертности среди взрослого населения. Цель исследования: сравнительный анализ морфо-функциональных изменений сердца, интракардиальной и системной гемодинамики у пациентов пожилого возраста с церебральным атеросклерозом (ЦА) 1-3 стадии и сахарным диабетом 2-го типа (СД2), в том числе в зависимости от полушарной локализации ишемического очага, и определение возрастных и половых различий у данной категории пациентов. Материал и методы: в комплексном исследовании приняли участие 229 пациентов с ЦА 1-3 стадии и СД2. Пациенты были разделены на 4 группы: 1-я группа — перенесшие ишемический инсульт (ИИ) в правом полушарии (ПП), 2-ая группа — перенесшие ИИ в левом полушарии (ЛП), 3-я группа — с ЦА 1-2 стадии (без ИИ — группа сравнения) и 4-я группа — общая группа пациентов, перенесших ИИ. Дизайн — исследование простое, проспективное, нерандомизированное, с последовательным включением пациентов. Результаты и обсуждение: Сравниваемые между собой группы статистически значимо различались по индексу ЛП, индексу конечно-диастолического размера, индексу конечно-систолического размера и толщине стенок левого желудочка (ЛЖ). Межполушарные отличия были зарегистрированы только в отношении величины ударного индекса. Эксцентрическая дилатационная гипертрофия ЛЖ (ГЛЖ) наблюдалась у пациентов с ИИ в 2,2 раза чаще, чем у пациентов с ЦА, а концентрическая дилатационная ГЛЖ встречалась у пациентов с ЦА 1-2 стадии в 1,8 раз чаще, чем у пациентов с ИИ. Межполушарные отличия наблюдались только в отношении III и V типов ГЛЖ. Для пациентов с ЦА 1-2 стадии и СД2 не установлены возрастные и половые различия в показателях структурно-функционального состояния сердца. Для пациентов с СД2, перенесших ИИ, характерны следующие возрастные и половые различия: статистически значимые большие размеры полости ЛЖ, ударногообъема (УО), минутного объема кровотока (МОК) и общего периферического сопротивления сосудов (ОПСС) присущи мужчинам, а статистически значимые меньшие размеры полости ЛЖ и большая толщина стенок ЛЖ наблюдаются после 60 лет. Выводы: у пациентов с ЦА 1-3 стадии наблюдаются статистически значимые отличия морфо-функциональных изменений сердца, интракардиальной и системной гемодинамики и геометрии ЛЖ, причем некоторые из этих отличий носят «полушарный» характер, а возрастные и половые различия характерны только для пациентов с ИИ и СД2.

Testing pterosaur ingroup relationships through broader sampling of avemetatarsalian taxa and characters and a range of phylogenetic analysis techniques.

The pterosaurs first appear in the fossil record in the middle of the Late Triassic. Their earliest representatives are known from Northern Hemisphere localities but, by the end of the Jurassic Period, this clade of flying reptiles achieved a global distribution, as well as high levels of diversity and disparity. Our understanding of early pterosaur evolution and the fundamental interrelationships within Pterosauria has improved dramatically in recent decades. However, there is still debate about how the various pterosaur subgroups relate to one another and about which taxa comprise these. Many recent phylogenetic analyses, while sampling well from among the known Triassic and Early Jurassic pterosaurs, have not included many non-pterosaurian ornithodirans or other avemetatarsalians. Given the close relationship between these groups of archosaurs, the omission of other ornithodirans and avemetatarsalians has the potential to adversely affect the results of phylogenetic analyses, in terms of character optimisation and ingroup relationships recovered. This study has addressed this issue and tests the relationships between the early diverging pterosaur taxa following the addition of avemetatarsalian taxa and anatomical characters to an existing early pterosaur dataset. This study has, for the first time, included taxa that represent the aphanosaurs, lagerpetids, silesaurids and dinosaurs, in addition to early pterosaurs. Anatomical characters used in other recent studies of archosaurs and early dinosaurs have also been incorporated. By expanding the outgroup taxa and anatomical character coverage in this pterosaur dataset, better resolution between the taxa within certain early pterosaur subclades has been achieved and stronger support for some existing clades has been found; other purported clades of early pterosaurs have not been found in this analysis—for example there is no support for a monophyletic Eopterosauria or Eudimorphodontidae. Further support has been found for a sister-taxon relationship between Peteinosaurus zambelli and Macronychoptera, a clade here named Zambellisauria (clade nov.), as well as for a monophyletic and early diverging Preondactylia. Some analyses also support the existence of a clade that falls as sister-taxon to the zambellisaurs, here named Caviramidae (clade nov.). Furthermore, some support has been found for a monophyletic Austriadraconidae at the base of Pterosauria. Somewhat surprisingly, Lagerpetidae is recovered outside of Ornithodira sensu stricto, meaning that, based upon current definitions at least, pterosaurs fall within Dinosauromorpha in this analysis. However, fundamental ornithodiran interrelationships were not the focus of this study and this particular result should be treated with caution for now. However, these results do further highlight the need for broader taxon and character sampling in phylogenetic analyses, and the effects of outgroup choice on determining ingroup relationships.

Effect of age on outcome in patients with cerebral stroke

The aim of the studywas to assess the course and outcome of cerebral infarction, depending on the age factor and duration of stay in the neuroblock. Materials and methods: a dynamic observation of 494 patients, men and women, aged 38–84 years with acute ischemic stroke of hemispheric localization, which were divided into the three groups depending on age, was performed. Group 1 – younger than 60 years old, group 2–60–70 years old, group 3 – older than 60 years. All patients underwent standard therapy, according to the recommendations for the treatment of ischemic stroke. The patients underwent comprehensive clinical and instrumental monitoring, which included assessment of somatic and neurological status according to the NIH‑NINDS scales at 1st, 3rd, 10th days and at discharge or death; assessment of the level of social adaptation according to the Bartel scale on 1st, 3rd, 10th days and at discharge, clinical and biochemical blood tests, computed tomography of the brain. Assessment of the quality of therapy was carried out according to specially developed maps using methods of statistical correlation analysis.Results:the most pronounced positive dynamics of neurological status was in the 1st group of patients. The regression of neurological deficit in the 2nd group was worse. The minimal dynamics of neurological deficit was in the 3rd group of patients with cerebral stroke. Most often, the death of patients with cerebral stroke occurred from the development of multiple organ disorders. Conclusions: patients over 70 years of age have the greatest risk of death, due to: a decrease in the reactivity of the body, the presence of initially severe concomitant somatic pathology in patients with admission to hospital; accession of secondary somatic and purulent‑septic complications.

Assessing Autonomic Nervous Function by Heart Rate Variability and Heart Rate Turbulence in Patients with Acute Ischemic Stroke.

Background:Acute ischemic stroke (AIS) induces adverse effects on the cardiovascular system by affecting the autonomic nervous system (ANS).Objectives:This study aimed to determine whether the parameters of heart rate variability (HRV) and heart rate turbulence (HRT) differed in patients with AIS as compared to that in the control group. Furthermore, we aimed to determine the differences in the involvement of the ANS between right and left hemisphere (LH) strokes.Methods:A total of 148 [74 right hemispheres (RH) and 74 left hemispheres] patients with AIS and 80 control subjects were included in the study. The Holter device was used to obtain elcctrocardiogram readings for over 20 h from all patients. Results of HRV and HRT parameters [Tonset (TO) and Tslope (TS)] were acquired through an automatic analysis of the program.Results:All HRV parameters were found to be low in patients with AIS (P < 0.05, for all parameters). TO and TS were disrupted in 99 patients with AIS (66.8%) and in 15 control subjects (18.7%) (HRT–1 and HRT–2 groups, P = <0.001). HRV parameters were detected to be similar in patients, irrespective of the left or right infarct. TO and TS were normal in 31 patients (41.9%) with left hemisphere localization and in only 18 patients (24.3%) with right hemisphere localization.Conclusions:Combined evaluation of HRV and HRT parameters may provide important information regarding the alterations in the ANS in patients with AIS. The utility of HRT in the determination of ANS alterations in patients with AIS should be investigated in larger future prospective studies.

Atherosclerosis and the Structural and Functional State of the Vessels of the Carotid and Vertebro-basilar Basins

In connection with modern pathogenetic ideas about the mechanisms of development of ischemic stroke, the early diagnosis of this disease becomes even more important. A relevant issue at the present stage is the information content of non-invasive ultrasound research methods used to study the state of the cerebral arteries that participate in the blood supply to the brain.The objective: to study the structural and functional state of the vessels of the carotid and vertebro-basilar pools in elderly patients with cerebral atherosclerosis (CA) of stage 1–3, including depending on the hemispheric localization of the ischemic focus.Materials and methods. 229 patients with CA of the 2nd – 3rd degree took part in a comprehensive clinical and instrumental study. Patients were divided into 4 groups: I – the general group of patients who underwent ischemic atherothrombotic stroke in the basin of the middle cerebral artery (IS); II – in the right hemisphere (RH); ІІІ – transferred IS in the left hemisphere (LH); ІV – with CA of 1–2 degree (without IS – comparison group). Subsequently, elderly patients from 55 to 75 years old participated in the comparison of groups.Results. In chronic cerebrovascular diseases, a steadily progressing atherosclerotic process is accompanied by a decrease in blood flow velocity in the main arteries of the head. Moreover, changes in LSBV (Linear systolic blood velocity) are detected by transcranial dopplerography at earlier stages both at the extra– and intracranial level, and blood flow depression initially occurs both in the arteries of the vertebro-basilar basin and in the carotid channel. The identification of changes in a Doppler study, in general, precedes the increase in symptoms of organic damage to the nervous system. Compared to patients with initial manifestations of CA, patients who underwent IS are characterized by a high frequency of hemodynamically significant stenosis, a thickening of complex intima-media, a statistically significant decrease in LSBV and an increase in pulsatory and peripheral resistance index in individual vessels of the carotid and vertebro basilar basins on both sides.Conclusion. Structural and functional features of cerebral vessels in patients after ischemic atherothrombotic stroke in the late recovery period have hemispheric features. Moreover, a statistically significant difference in the rate of cerebral blood flow was observed only in the vessels of the carotid basin on the right, and the indices of peripheral vascular resistance and pulsativity were increased in different vessels of both pools from 2 sides.

Sexual Dimorphism Within Brain Regions Controlling Speech Production.

Neural processing of speech production has been traditionally attributed to the left hemisphere. However, it remains unclear if there are structural bases for speech functional lateralization and if these may be partially explained by sexual dimorphism of cortical morphology. We used a combination of high-resolution MRI and speech-production functional MRI to examine cortical thickness of brain regions involved in speech control in healthy males and females. We identified greater cortical thickness of the left Heschl’s gyrus in females compared to males. Additionally, rightward asymmetry of the supramarginal gyrus and leftward asymmetry of the precentral gyrus were found within both male and female groups. Sexual dimorphism of the Heschl’s gyrus may underlie known differences in auditory processing for speech production between males and females, whereas findings of asymmetries within cortical areas involved in speech motor execution and planning may contribute to the hemispheric localization of functional activity and connectivity of these regions within the speech production network. Our findings highlight the importance of consideration of sex as a biological variable in studies on neural correlates of speech control.

The Relationship Between Rhythm Variability and the Structural and Functional State of the Heart in Patients with Cerebral Atherosclerosis

The objective: to identify the presence of relationships between indicators of HRV and the structural and functional state of the heart in patients with cerebral atherosclerosis (CA) stage 1–3, depending on the hemispheric localization of the ischemic focus.Materials and methods. In a comprehensive study, 229 patients with CA 1–3 rd degree took part. The patients were divided into 4 groups: І - those who had ischemic stroke (IS) in the right hemisphere (RH); II – transferred IS in the left hemisphere (LH); ІІІ – with CA of 1st – 2nd degree (without IS – comparison group); IV – a general group of patients who have undergone ischemic atherothrombotic stroke. The age of patients of the examined groups ranged from 55 to 75 years. All patients underwent transthoracic echocardiography and an ECG with an assessment of heart rate variability (HRV). Statistical analysis was performed using non-parametric methods (Mann – Whitney test, Spearman’s rank correlation coefficient). Results are presented as medians and 25%, 75% quartiles. To identify the relationship between the indicators of the structural and functional state of the heart and HRV, a correlation analysis was carried out with the calculation of the Spearman’s rank correlation coefficient.Results. In the general group of patients undergoing IS, one inverse correlation was established between the indices of the left ventricular myocardial mass index (MMI) and LF/HF% (r=–0,298), and in the group of patients without IS with CA 1–2 stages were established to relate the index of the relative wall thickness of the LV with the HRV and LF/HF indices (r=–0,196 and r=0,183 respectively) and 2 links of the LV diastolic myocardial function index with HRV and the triangular index (r=0,202 and r=0,217 respectively). When comparing groups of patients with different localization of IS, it was found that for patients with IS in the L, there is a characteristic of 3 MMLV connections with PNN50% and LF/HF% (0,322, –0,304 and –0,373 respectively), whereas for patients with the localization of IS in RH links no links were established.Conclusions. In patients with cerebral atherosclerosis without ischemic stroke, a decrease in HRV with activation of the sympathetic nervous system is associated with concentric LV remodeling and more severe left ventricular diastolic dysfunction. The presence of an ischemic focus in the left hemisphere of the brain, in contrast to the right hemisphere, determines more pronounced changes in HRV in patients as the degree of LV hypertrophy increases, which determines the high risk of repeated vascular events.

ОСОБЛИВОСТІ СТРУКТУРНО-ФУНКЦІОНАЛЬНОГО СТАНУ СЕРЦЯ У ПАЦІЄНТІВ НА РІЗНИХ СТАДІЯХ ЦЕРЕБРАЛЬНОГО АТЕРОСКЛЕРОЗУ

Cerebrovascular diseases is one of the most important causes of morbidity and mortality in the adult population. Objective: to conduct a comparative analysis of the morpho-functional changes of the heart, intracardiac and systemic hemodynamics in elderly patients with cerebral atherosclerosis (CA) of 1–3 degree. Materials and methods: 229 patients with cerebral atherosclerosis of 2–3 degree took part in a comprehensive study. The patients were divided into 4 groups: Group 1 – patients with ischemic stroke (IS) in the right hemisphere (RH), Group 2 ­– with IS in the left hemisphere (LH), Group 3 – with cerebral atherosclerosis of 1–2 degree (no IS – comparison group) and Group 4 – a general group of patients who have IS. Design: simple, prospective, non-randomized, with the consistent inclusion of patients. Results and discussion: The compared groups differed statistically significantly by the LA diameter index (ILA), the LV diastolic index (LVIDd), the LV systolic index (LVIDs) and the wall thickness of the left ventricle (LV). Thus, the highest ILA value was observed in patients with CA (1.1 times more than in patients with IS), the highest values of LVIDd and LVIDs – in the group of patients with left-hemispheric localization of IS (1.14 and 1.18 times more, accordingly, than in patients with CA without IS). The minimal thickness of the interventricular septum (IVS) and the posterior wall of the LV was in the group of patients with CA (1.18 and 1.17 times less, respectively, compared with the group of patients with AI, without taking into account the hemispheric localization of IS). Interhemispheric differences were observed only in the assessment of LVIDd, LVIDs, and the thickness of the IVS. So, in patients with left hemispheric localization of IF LVIDd, it was 1.09 times greater, and LVIDs was 1.16 times greater than in patients with right hemispheric IF, while the IVS was 1.15 times thicker in the IS ​​group with the right hemisphere than with left hemispheric localization of IF. In the compared groups, we also observed statistically significant differences in the assessment of the parameters of systemic and intracardiac hemodynamics. So, in patients with CA, the index of the end-diastolic volume (iEDV) was 1.14 times higher and the index of the end-systolic volume (iESV) was 1.09 times less than in patients with IS, while in patients with left-hemispheric localization of IS the lowest ejection fraction and iEDV were observed compared with the group of patients with CA (1.02 and 1.15 times, respectively). Interhemispheric differences were recorded only in terms of the magnitude of the stroke index (SI). Thus, patients with IS in LН SI was 1.2 times more than in patients with IS in RH. In the group of patients with CA and IS, non-dilatational eccentric and concentric hypertrophy of LV (LVH) was most common (37.4 % and 48.1 %–26.0 % and 61.6 %, respectively), but type III was 1.44 times more common in patients with CA, and type V – 1.28 times more often in patients with IS. Eccentric dilated LVH was most often observed in patients with IS – 2.2 times more often than in patients with CA, and concentric dilated LVH was more common in patients with CA – 1.8 times more often than in patients with IS. Interhemispheric differences were observed only in relation to types III and V LVH. Thus, in patients with right hemispheric localization of IF, concentric non-dilated LVH was 1.66 times more common, and in patients with left-hemispheric IF localization – 4.4 times eccentric non-dilated LVH. Conclusions: in patients with CA of 1–3 degree, there were statistically significant differences in the morpho-functional changes in the heart, intracardiac and systemic hemodynamics and LV geometry, and some of these differences were hemispheric.

TRANSFORMATION OF ARRESTED SMALL-MOTOR MOVEMENTS IN AUTOMATED IN THE PROCESS OF RETROACTIVE TRAINING OF PATIENTS WITH ISCHEMIC STROKE

Objective: to study the transformation of arbitrary small motor motions into automated (which form the basis of self-service skills) in the process of restorative education of patients who underwent ischemic stroke. Materials and methods: the material of the study is a sample of patients who underwent ischemic stroke, hemispheric localization (53 people). As a method, a complex of neuropsychological tests, hardware methods of diagnostics and restorative training were used. Results: The dynamics of restoration of small motor motions in automated actions that make up self-care skills for patients who underwent ischemic stroke, regardless of the lateralization profile and hemispheric localization of the lesion focus, is characterized by self-sufficient precision performance of automated small-engine actions that constitute self- service skills. It is established that there is no degeneration of the formed skills in time, provided it is used periodically; as well as a positive motivation to use the formed skills of self-service.

TRANSFORMATION OF ARRESTED SMALL-MOTOR MOVEMENTS IN AUTOMATED IN THE PROCESS OF RETROACTIVE TRAINING OF PATIENTS WITH ISCHEMIC STROKE

Objective: to study the transformation of arbitrary small motor motions into automated (which form the basis of self-service skills) in the process of restorative education of patients who underwent ischemic stroke. Materials and methods: the material of the study is a sample of patients who underwent ischemic stroke, hemispheric localization (53 people). As a method, a complex of neuropsychological tests, hardware methods of diagnostics and restorative training were used. Results: The dynamics of restoration of small motor motions in automated actions that make up self-care skills for patients who underwent ischemic stroke, regardless of the lateralization profile and hemispheric localization of the lesion focus, is characterized by self-sufficient precision performance of automated small-engine actions that constitute self- service skills. It is established that there is no degeneration of the formed skills in time, provided it is used periodically; as well as a positive motivation to use the formed skills of self-service.

Analysis of the clinical features and course of seizures in patients with brain tumors

Verify material of 125 patients with brain tumors and associated convulsions assessed the frequency and characteristics of existing epileptic seizures. It is found that convulsions complicate the disease more often in tumors of low-grade and left hemisphere localization. Simple partial paroxysms more characterize to right-hemisphere, and the complex – to left-hemispheric localization. The clinic of brain tumor begins with a convulsion often in surface localization process.

PATHOGENETIC FEATURES OF FUNCTIONAL STATE OF THE BRAIN AND CARDIAC CEREBRAL RELATIONSHIPS IN PATIENTS WITH ATHEROTHROMBOSIS AND CARDIOEMBOLIC STROKE

The article presents data on the effect of Mexicor in patients who underwent cardioembolic stroke. Thus, Mexicor improves cerebral hemodynamics in Posterior cerebral circulation and causes a reorganization of the structure of brain bioelectrical activity and the type of frequency-amplitude reorganization is determined by the hemispheric localization of the stroke, which may be due to different hemispheres connection with regulating mesencephalic structures and synchronizing diencephalic structures of the brain. In patients with localization of ischemic lesion in the right hemisphere, Mexicor statistically significantly increases the power in the range of α1-, α2-rhythms in the affected and intact hemispheres, which indicates the active influence of the drug on the synchronizing diencephalo-talamic structures of the brain. In patients with localization of ischemic lesion in the left hemisphere, Mexicor predominantly reduces power in the range of slow rhythms and in the range of β2 rhythms in the two hemispheres, which is caused by increased metabolic and functional activity of the mesencephalic stem brain structures. In patients undergoing cardioembolic stroke, Mexicor has a harmonizing effect on the bioelectrical activity of the brain, and improves cerebral hemodynamics, which gives grounds to recommend the use of Mexicor for the rehabilitation of patients who have undergone cardioembolic stroke.

Variability of motor performance and symptoms of motor disregard in the use of neurocomputer technologies in the rehabilitation of patients after a stroke

Currently, neurobiological feedback technologies based on neurocomputer interfaces are used in the rehabilitation of patients after a stroke (Yekutiel M, 2000). The ability to actively implement the capabilities of interface-brain-computer technology (IMC) remains limited for most patients (Cloutier S. et al., 2015). The IMC was used, based on the analysis of EEG patterns and recognition of the synchronization / desynchronization reaction of the sensoro-motor (mu-rhythm) in imagining the movements of the hands of patients. The data of 15 patients (7 men, 8 women), at the age of 64 (62.0, 69.0) years, the duration of the stroke of 8 (5, 19) months, with right hemispheric localization in 7 patients (46%), mild to plegia (MRCWS); with a focus of stroke etiology (ischemic / hemorrhagic), supratentorial localization (CT, MRI); received therapy IMK-an exoskeleton brush with kinesthetic feedback, 9.5 (8; 10) procedures (ClinicalTrials.gov (identifier: NCT02325947 )). Only 6 (40%) patients solved the mental motor problem with accuracy of the EEG data (presence of the mu-rhythm) above 70%, 4 (26%) failed to solve the problem. The accuracy of their representations according to EEG data was no more than 20%. The accuracy of the representations of the remaining 5 (33%) patients was in the range of 45–55%. What is consistent with the literature (Ahn and Chan, 2015; Hammer EM et al., 2014). The absolute majority of patients with stroke have motor disregard for the affected side. Even with a minimal motor deficit, patients unconsciously prefer to use a healthy hand in everyday life. Such patients need to restore the functional system of formation of target motility by training the lost or altered links of this functional system. The combination of neurocomputer technologies (IMC) and physical training in a certain sequence will facilitate their more successful interaction and will improve the efficiency of rehabilitation.

Tantrums, Emotion Reactions and Their EEG Correlates in Childhood Benign Rolandic Epilepsy vs. Complex Partial Seizures: Exploratory Observations.

We explored associations between EEG pathophysiology and emotional/behavioral (E/B) problems of children with two types of epilepsy using standard parent questionnaires and two new indicators: tantrums recorded by parents at home and brief, emotion-eliciting situations in the laboratory. Children with Benign Rolandic epilepsy (BRE, N = 6) reportedly had shorter, more angry tantrums from which they recovered quickly. Children with Complex Partial Seizures (CPS, N = 13) had longer, sadder tantrums often followed by bad moods. More generally, BRE correlated with anger and aggression; CPS with sadness and withdrawal. Scores of a composite group of siblings (N = 11) were generally intermediate between the BRE and CPS groups. Across all children, high voltage theta and/or interictal epileptiform discharges (IEDs) correlated with negative emotional reactions. Such EEG abnormalities in left hemisphere correlated with greater social fear, right hemisphere EEG abnormalities with greater anger. Right hemisphere localization in CPS was also associated with parent-reported problems at home. If epilepsy alters neural circuitry thereby increasing negative emotions, additional assessment of anti-epileptic drug treatment of epilepsy-related E/B problems would be warranted.

Magnetostratigraphy across the Triassic-Jurassic boundary in the main Karoo Basin

The end-Triassic mass extinction and the transition and explosive diversification of fauna over the Triassic-Jurassic boundary is poorly understood and poorly represented in the rock record of the Southern Hemisphere. This is despite the rich diversity in both body and trace fossils of Triassic-Jurassic age in southern Africa, which is not found in coeval Northern Hemisphere localities. We report here the first palaeomagnetic polarity zonation of the Upper Triassic-Lower Jurassic continental red bed succession (Elliot Formation; Stormberg Group) in southern Africa. The results from 10 partially overlapping sections, with a composite thickness of ~280m, provide a magnetic polarity chronology of the main Karoo Basin in South Africa and Lesotho. Palaeomagnetic analyses reveal that heating samples to between 150°C and ~300°C removes the secondary, moderately inclined (~48°) normal-polarity component of remanent magnetization. This component overlaps with the present-day field and is comparable to the overprint direction expected from Lower Jurassic Karoo dolerite intrusions. In contrast, a likely primary, high unblocking temperature component, of dual polarity, consistently is of steeper inclination (~63°). This characteristic remanence passes the reversals test, except where means are based on small sample populations. There are only two resulting polarity zones for the ~200m thick lower Elliot Formation (LEF) with potential for a thin 3rd magnetozone in the uppermost part. The upper Elliot Formation (UEF), in contrast, which was sampled over a thickness of ~ 80 m, has five polarity zones. The failure of the reversal test for the UEF and combined Elliot Formation (LEF+UEF) indicates that the normal polarity samples may be biased by a younger overprint of either the Jurassic normal polarity of the Karoo Large Igneous Province or present day field. The separate poles calculated for the four sites in the LEF and ten sites in the UEF overlap with the Late Triassic and Early to Middle Jurassic Gondwana poles, respectively. The combined Elliot Formation and UEF pole positions are better constrained than the LEF and therefore considered more reliable. Overall the LEF shows considerable overlap with the Late Triassic Apparent Polar Wander Paths (APWP) poles.

Reciprocal organization of constructive activity in patients with ischemic stroke

To study the organization of reciprocal constructive activity in patients with ischemic stroke based on hemispheric localization of the lesion and the profile of lateral organization in a segment of leading hand. The study included 57 post-stroke patients. An experimental method and a set of neuropsychological tests were used. There was an overall decline in the parameters of constructive activity (accuracy and rate) in patients with ischemic stroke, regardless of localization of the lesion and the profile of lateral brain organization in the segment of leading hand. Constructive activities of left-handed patients with right-hemisphere stroke and right-handed patients with left-hemisphere lesions are regulated by reciprocal and dynamic organization of praxis functions. In right-handed patients with right hemisphere ischemic stroke and left-handed patients with left-hemisphere lesions, constructive activities are regulated by the kinetic-kinesthetic organization of the motor act, dynamic organization of the motor act that characterizes the reciprocal organization.

Fossil Cetaceans (Mammalia, Cetacea) from the Neogene of Colombia and Venezuela

There are significant geographic gaps in our knowledge of marine mammal evolution because most fossils have been found and described from Northern Hemisphere localities and a few other high-latitude areas in the Southern Hemisphere. Here, we describe fossil cetacean remains from five geological units in the South American tropics (Urumaco, Codore, Castilletes, Cantaure, and Querales formations) generally representing marginal marine depositional environments (estuaries, deltas, and tidal flats). While fossil cetaceans from Venezuelan Neogene localities have been previously studied, this paper includes the first descriptions of fossil cetaceans from Colombia, including a diverse assemblage of mysticetes and odontocetes. We identified and provisionally referred fragmentary remains to the iniid Ischyrorhynchus vanbenedeni and to the platanistid Zarhachis flagellator. The latter suggests the presence of Platanistidae in the eastern coast of South America during the early-middle Miocene, representing the second record of Platanistidae in South America and the first record of Platanistidae in eastern South America. Other less-diagnostic specimens are characterized by features commonly seen in longirostrine odontocetes such as Iniidae, Platanistidae, Pontoporiidae, Lipotidae, Eoplatanistidae, and Squalodelphinidae.

The Toarcian Oceanic Anoxic Event (Early Jurassic) in the Neuquén Basin, Argentina: A Reassessment of Age and Carbon Isotope Stratigraphy

AbstractThe Toarcian oceanic anoxic event (T-OAE) is recorded by the presence of globally distributed marine organic carbon–rich black shales and a negative carbon isotope shift, with δ13Corg values as low as −33‰, interrupting an overarching positive excursion. Here we present new biostratigraphic data and high-resolution δ13Corg data from two Southern Hemisphere localities: Arroyo Serrucho in the north and Arroyo Lapa in the south of the Neuquen Basin, Argentina. Previous studies at these localities aimed to provide an accurate numerical age for the T-OAE and characterization of its carbon isotope stratigraphy. The new carbon isotope data and ammonite biostratigraphy presented here from Arroyo Serrucho show the T-OAE to be recorded lower in the section than supposed by previous authors, thus calling into question the published age of the T-OAE in this section. A newly investigated exposure at Arroyo Lapa North shows a complex carbon isotope record with at least three high-amplitude fluctuations in the h...

Topographic congruence of calcified parenchymal neurocysticercosis and other structural brain lesions with epileptiform activity.

Introduction:Calcified parenchymal neurocysticercosis (NCC) lesions are commonly detected in many individuals with refractory epilepsy. However, the relationship between these lesions and epilepsy is not fully determined. We sought to determine if calcified parenchymal NCC demonstrated topographic congruence with epileptiform activity in refractory epilepsy patients. Additional patients with other structural brain lesions were included for comparison.Subjects and Methods:Retrospective cross-sectional analysis of all patients treated at a community-based neurology clinic for refractory epilepsy during a 3-month period and with structural brain lesions detected by neuroimaging studies.Results:A total of 105 patients were included in the study, including 63 with calcified parenchymal NCC lesions and 42 with other structural brain lesions. No significant relationship was detected between hemispheric localization of calcified parenchymal NCC lesions and epileptiform activity. For those with other structural brain lesions, the hemispheric localization was significantly related to the side of epileptiform activity (Chi-square = 11.13, P = 0.025). In addition, logistic regression models showed that those with right-sided non-NCC lesions were more likely to have right-sided epileptiform activity (odds ratio = 4.36, 95% confidence interval [CI] =1.16–16.31, P = 0.029), and those with left-sided non-NCC lesions were more likely to have left-sided epileptiform activity (odds ratio = 7.60, 95% CI = 1.89–30.49, P = 0.004).Conclusion:The lack of correlation between the side of calcified parenchymal NCC lesions and the side of the epileptiform activity suggests that these lesions may be incidental findings in many patients.

Distinct lower visual field preference for object shape.

Humans manipulate objects chiefly within their lower visual field, a consequence of upright posture and the anatomical position of hands and arms.This study tested the hypothesis of enhanced sensitivity to a range of stimuli within the lower visual field. Following current models of hierarchical processing within the ventral steam, discrimination sensitivity was measured for orientation, curvature, shape (radial frequency patterns), and faces at various para-central locations (horizontal, vertical, and main diagonal meridians) and eccentricities (5° and 10°). Peripheral sensitivity was isotropic for orientation and curvature. By contrast, observers were significantly better at discriminating shapes throughout the lower visual field compared to elsewhere. For faces, however, peak sensitivity was found in the left visual field, corresponding to the right hemispheric localization of human face processing. Presenting head outlines without any internal features (e.g., eyes, mouth) recovered the lower visual field advantage found for simple shapes. A lower visual field preference for the shape of an object, which is absent for more localized information (orientation and curvature) but also for more complex objects (faces), is inconsistent with a strictly feed-forward model and poses a challenge for multistage models of object perception. The distinct lower visual field preference for contour shapes is, however, consistent with an asymmetry at intermediate stages of visual processing, which may play a key role in representing object characteristics that are particularly relevant to visually guided actions.