Spontaneous Restoration Research Articles

Modifying effect of ant colonization on soil heterogeneity along a chronosequence of tropical forest restoration on slash-burn lands

Ants act as ecosystem engineers in regulating soil heterogeneities. Little is known about the degree and direction of these modifications on soils across a restoration chronosequence of tropical forests. Our objectives aimed to explore the effect of belowground-nesting ants on soil characteristics across four forest restoration stages (i.e., 12-, 28-, 42- and 53-yr olds) on slash-burn lands in the tropical Xishuangbanna, southwestern China. We confirmed the hypotheses about a positive effect of ant colonization on soil physical characteristics, and on the enrichment of microbial carbon and mineral nutrients in nest soils across the four restoration stages. Ant nests had the highest enrichment of soil organic matter (103%), readily oxidizable carbon (78%), total nitrogen (114%), available nitrogen (126%), NH4+ (133%) and NO3– (140%) at the 12-yr old stage compared with the surrounding soils. In contrast, the highest enrichment of microbial carbon (110%) in nest soils was showed at the 53-yr old stage. The enrichment of microbial carbon in nest soils increased with restoration age, but that of soil mineral nutrients would not follow the forest restorations. A higher enrichment of mineral nutrients in nest soils at the early restoration stage can improve soil fertility, which might promote the spontaneous forest restorations. A higher abundance and area of ant nests at the older restoration stage may create a higher bare space for plant development. Therefore, our results suggest that ant colonization can regulate forest restorations, possibly through creating and maintaining higher soil nutrient heterogeneity at earlier stage, and greatly stirring microbial growth and opening up space for plant development at older stage on slash-burn tropical lands.

Genome-wide association study to identify genomic regions influencing spontaneous fertility in maize haploids

Efficient production and use of doubled haploid lines can greatly accelerate genetic gains in maize breeding programs. One of the critical steps in standard doubled haploid line production is doubling the haploid genome using toxic and costly mitosis-inhibiting chemicals to achieve fertility in haploids. Alternatively, fertility may be spontaneously restored by natural chromosomal doubling, although generally at a rate too low for practical applications in most germplasm. This is the first large-scale genome-wise association study to analyze spontaneous chromosome doubling in haploids derived from tropical maize inbred lines. Induction crosses between tropicalized haploid inducers and 400 inbred lines were made, and the resulting haploid plants were assessed for haploid male fertility which refers to pollen production and haploid fertility which refers to seed production upon self-fertilization. A small number of genotypes were highly fertile and these fertility traits were highly heritable. Agronomic traits like plant height, ear height and tassel branch number were positively correlated with fertility traits. In contrast, haploid induction rate of the source germplasm and plant aspect were not correlated to fertility traits. Several genomic regions and candidate genes were identified that may control spontaneous fertility restoration. Overall, the study revealed the presence of large variation for both haploid male fertility and haploid fertility which can be potentially exploited for improving the efficiency of doubled haploid derivation in tropical maize germplasm.

MON-LB070 Lymphocytic Infundibulo-Neurohypophysitis Producing Regressive Postpartum Diabetes Insipidus

Background : Lymphocytic Infundibulo-neuro-hypophysitis (LINH) is a rare autoimmune disease that typically presents as acute onset diabetes insipidus (DI) with intracranial mass-effect symptoms. The diagnosis is based on: clinical features, electrolyte and hormonal dosages, MRI imaging and coexistence of other autoimmune disorders; sometimes autoantibodies to AVP-secreting cells (AVPcAb) are detected (1). Clinical case: We present the rare case of a 25 years old female patient presenting in an outpatient clinic, 4 months postpartum, with polyuria and polydipsia, intense headache and visual disturbances (blurred view and fatigue at reading). A diagnosis of central diabetes insipidus (CID) was established based on: dilute urine, low natriuria, negative fluid deprivation test and positive response to desmopressin. A treatment with desmopressin (Minirin Melt®) 2X120 mcg/day was prescribed, followed by the remission of polyuria and polydipsia but persistence of the headache. No imaging was performed at the time and the patient was lost from follow-up. After 22 months she was admitted in our service for further evaluation complaining of persistent daily headache, and intolerance to the initial doses of desmopressin producing intense and pulsatile headache short time after administration. The initial visual disturbances were now remitted. Analysis confirmed CDI by spontaneous dilute urine, negative fluid deprivation test, but good response to low doses of desmopressin (60 mcg Minirin Melt®). Antidiuretic hormone (ADH) level, at the end of the fluid deprivation test, was in the low values of the normal (2.3 pg/ml, n.r. 2-8 ) pointing to a partial restoration of ADH secretion. MRI imaging showed absence of the bright spot of neuro-hypophysis and slight enlargement of the pituitary stalk with enhanced contrast, characteristic features of lymphocytic infundibulo-neuro-hypophysitis (2). Pituitary biopsy and AVPcAb or Rabphilin (Rab) antibody dosage were not available. Adeno-hypophysis hormones and peripheral hormones were in the normal range, showing adeno-hypophysis integrity. No other autoimmune diseases were detected. Treatment with desmopressin was reinstated with lower doses (Minirin Melt® 2X60 mcg/day) followed by remission of polyuria and polydipsia and good tolerance. Taking into account the evolution of the disease, in the future months we expect a complete remission of the CDI. Conclusion: We present a rare case of postpartum CDI produced by LINH evolving towards spontaneous restoration of the ADH secretion.

The spontaneous restoration of the course of psoas muscles after corrective surgery for adult spinal deformity

BackgroundA previous study demonstrated that spinopelvic alignment and morphology influence a deviation in the course of psoas muscle (PM). However, it is unknown whether such deviations might be caused by a decrease in lumbar lordosis (LL) or the lateral deviation of the lumbar spine following scoliosis. The purpose of this study was to elucidate the close relationship between the coronal and sagittal lumbar alignment and a deviation in the course of PM. MethodsWe investigated the preoperative and postoperative spinopelvic parameters and the morphology of PM at L4/5 level in 30 patients treated with corrective surgery for adult spinal deformity who were diagnosed with “rising psoas sign” before surgery. Spinopelvic parameters were measured on X-ray films. Investigation of the morphology of PM and the morphological measurements were performed using computed tomography (CT) images. The “rising psoas sign” was classified as bilateral- or unilateral-type as defined in the previous study. ResultsAmong 18 patients who had bilateral-type rising psoas sign before surgery, 11 patients remained bilateral-type after surgery despite an increase in LL. The pelvic incidence of these 11 patients was significantly larger than that of the other 7 patients (53.5 ± 10.2° vs 43.2 ± 5.8°) (p = 0.037). The magnitude of postoperative increase in LL positively correlated with that of the posterior shift of PM (r = 0.41, p = 0.025). The degree of restoration of the lumbar spine following scoliosis was positively correlated with that of the medial shift of PM (r = 0.66, p = 0.025). ConclusionThe decrease in LL and the lateral deviation of lumbar spine following scoliosis caused a deviated course of the PM, which was spontaneously corrected by the restoration of lumbar alignment. However, the bilateral-type deviation in patients with higher pelvic incidence was considered to be within the range of normal variation.

Genetic dissection of haploid male fertility in maize (Zea mays L.)

AbstractHaploid genome doubling is a key limiting step of haploid breeding in maize. Spontaneous restoration of haploid male fertility (HMF) provides a more promising method than the artificial doubling process. To reveal the genetic basis of HMF, haploids were obtained from the offspring of 285 F2:3 families, derived from the cross Zheng58 × K22. The F2:3 families were used as the female donor and Yu high inducer No. 1 (YHI‐1) as the male inducer line. The rates of HMF from each family line were evaluated at two field sites over two planting seasons. HMF displayed incomplete dominance. Transgressive segregation of haploids from F2:3 families was observed relative to haploids derived from the two parents of the mapping population. A total of nine quantitative trait loci (QTL) were detected, which were distributed on chromosomes 1, 3, 4, 7 and 8. Three major QTL, qHMF3b, qHMF7a and qHMF7b were detected in both locations, respectively. These QTL could be useful to predict the ability of spontaneous haploid genome doubling, and to accelerate the haploid breeding process by introgression or aggregation of those QTL.

Spontaneous and assisted restoration of vegetation on the bottom of a former water reservoir, the Elwha River, Olympic National Park, WA, U.S.A.

Early seral vegetation was studied on a former lake bottom after the removal of the 64‐m‐tall Glines Canyon Dam on the Elwha River. In 2015, vegetation cover of all vascular plant species was determined in 63 plots located on sites that emerged in 2011–2012. The sites had been planted and/or seeded, or were permitted to revegetate spontaneously. The plots were further classified by substrate texture: coarse sediments on the valley bottom and fine ones on the valley slopes. Plots were located randomly along random transects perpendicular to the former lake shore that extended into coarse sediment terraces perched above the floodplain. Additionally, 32 plots were sampled in surrounding native forests near these transects. Data were analyzed by detrended correspondence analysis and by canonical correspondence analysis. Substrate texture, that is whether fine or coarse, appeared to explain most of the variability in vegetation. The distance to forest and successional age, that is time since the site had been drained, were also significant explanatory variables, while assisted restoration by planting and seeding appeared to be insignificant to date. Spontaneous succession on fine sediments led to a species composition approaching that of adjacent natural forests. Invasive species were much less abundant than expected. Spontaneous restoration of vegetation on fine sediments in drained lake bottoms can rapidly produce a desirable vegetation composition and structure. On coarse sediments, active restoration may be useful to accelerate the development of native vegetation communities.

Diagnóstico ecológico, formulación e implementación de estrategias para la restauración de un bosque seco tropical interandino (Huila, Colombia)

El diagnóstico ecológico regional es fundamental para planificar procesos de restauración ecológica (RE), especialmente en ecosistemas poco conocidos y amenazados como el Bosque Seco Tropical (bs-T). A partir del diagnóstico ecológico de un bs-T en el departamento del Huila, Colombia, se formuló, implementó e inició el monitoreo de seis estrategias para su restauración. Para los escenarios de restauración se identificaron las barreras a la regeneración natural y sus facilitadores, los ecosistemas de referencia y las especies clave. Con esta información se formularon seis estrategias de restauración: i) nucleación en pastizales abiertos con núcleos entre 2x2 m y 32x32 m con variación en el número de especies (3–30), número de individuos (9–196), ensambles de especies (1–4) y manejo del suelo, ii) siembra bajo árboles nodriza en pastizales arbolados con 37 individuos de seis especies, iii) siembra bajo agrupaciones de árboles con 57 individuos de once especies, iv) ampliación de borde de bosques y arbustales con fajas de 10x5 m con 17 individuos de cinco especies, v) enriquecimiento en arbustales y bosques en módulos hexagonales monoespecíficos de siete individuos, y vi) restauración espontánea. La siembra total fue de 54 300 individuos con mayor esfuerzo en la nucleación de 32x32 m con 159 réplicas y 21 676 individuos. El monitoreo a largo plazo permitirá evaluar el desarrollo de trayectorias sucesionales acorde con las referencias y determinar el costo efectividad de las estrategias. Este proceso metodológico de diagnóstico ecológico, formulación, implementación y monitoreo de estrategias puede servir como guía importante para la RE del bs-T en otras localidades.

OPTIMIZATION OF THE HEART RATE CONTROL IN ATRIAL FIBRILLATION BY MONITORING OF THE DIGOXIN CONCENTRATION IN ELDERLY PATIENTS

Background. Digoxin takes important place in the management of patients with paroxysmal or persistent atrial fibrillation (AF). Monitoring of serum digoxin concentration (SDC) seems to be perspective way to improve the safety and efficacy of treatment. At the same time, there are no generally accepted reference ranges for SDC, especially in terms of the onset of therapy.Aim. To evaluate the potential contribution of SDC monitoring in the context of efficacy of AF treatment with the use of digoxin in elderly patients.Material and methods. A retrospective analysis of treatment of patients with recent-onset (n=91) or permanent (n=58) AF was performed. In all cases, the strategy of heart rate (HR) control was realized, including treatment with digoxin in 104 cases. SDC was measured twice during the digitalization: 20 hours after the first digoxin dose, and at the endpoint (time of sinus rhythm spontaneous restoration or, if the rhythm not restored, on day 7 of AF persistence).Results. The influence of digoxin on HR was dose-dependent since the 1st week of therapy, and the SDC dynamics was strictly associated with change in HR (r=-0.66, p<0.001). There was a negative correlation between the probability of the sinus rhythm restoration due to digoxin therapy and the SDC: its probability in high SDC was significantly lower compared to other approaches to the HR control (0% vs 76% in beta-blocker monotherapy; and vs 100% in therapy with beta-blocker + lower-SDC, p=0.036). In patients with persisted AF and low SDC, the digoxin was withdrawn more often due to lack of clinical efficiency.Conclusions. The SDC monitoring at the 1st week of digitalization could be used to improve the efficacy of therapy and to minimize the risks of spontaneous rhythm restoration, if not desired, and to reveal the disproportion between its high dose and low efficacy. The role of this diagnostic tool seems to be limited to safety control and negative predictive value for efficacy (the lower concentration, the higher risk of inefficiency), whereas its positive predictive value in terms of efficacy seems contradictory. The obtained data could be used for decision-making for recommendation of longterm digoxin usage if its contribution into HR control is doubtful.

Temporary Pacemakers - Step by Step

Symptomatic bradycardia is usually caused by abnormalities of atrioventricular conduction or sinus node dysfunction. Reversible and irreversible causes must be considered.Temporary pacemakers are used in the emergency treatment in case of severe bradyarrhythmia.They help to bridge the acute phase until spontaneous restoration of atrioventricular or sinus node function or -if spontaneous restoration fails- until a permanent pacemaker system was implanted.In the following article we discuss the commonly used temporary pacemaker systems. We demonstrate their use and correct programming by an illustrated step by step explanation. For troubleshooting a flow chart was added.

Non-Hermitian lattices with a flat band and polynomial power increase [Invited

In this work we first discuss systematically three general approaches to construct a non-Hermitian flat band, defined by its dispersionless real part. They resort to, respectively, spontaneous restoration of non-Hermitian particle-hole symmetry, a persisting flat band from the underlying Hermitian system, and a compact Wannier function that is an eigenstate of the entire system. For the last approach in particular, we show the simplest lattice structure where it can be applied, and we further identify a special case of such a flat band where every point in the Brillouin zone is an exceptional point of order 3. A localized excitation in this "EP3 flat band" can display either a conserved power, quadratic power increase, or even quartic power increase, depending on whether the localized eigenstate or one of the two generalized eigenvectors is initially excited. Nevertheless, the asymptotic wave function in the long time limit is always given by the eigenstate, and in this case, the compact Wannier function or its superposition in two or more unit cells.

Рідкісний випадок спонтанного тромболізису у пацієнтки з гострим інфарктом міокарда з елевацією сеґмента ST

In the pathogenesis of acute myocardial infarction an important role belongs to coronary sclerosis and coronary artery thrombosis. Endothelium plays an important role in a regulation of vascular tone, local inflammation, hemostasis, neovascularisation. An impairment of endothelial barrier function occurs after direct damage of endothelial cells as a result of an atherosclerotic plaque destabilization, injury, chronic inflammation or exposure to hazardous substances. Breakage of the endothelial surface causes an exposure of subendothelial collagen and triggers expression of adhesive proteins (e.g. tissue factor and von Willebrand factor) and decreases synthesis of prostacyclin and nitric oxide. In case of its damage and activation, thrombocytes adhere and aggregate to each other which leads to thrombosis and can cause an acute myocardial infarction.  Aim. Our aim was to evaluate a cellular mechanisms of thrombosis as well as conditions that leads to spontaneous thrombolysis in acute myocardial infarction for treatment optimisation of acute coronary syndrome.   Material and Methods. The case of acute myocardial infarction with ST segment elevation in 79 years old patient is presented that showed spontaneous coronary blood flow recovery.  Results and Discussion. In described case in a patient with acute myocardial infarction a rapid regression of ECG changes were documented after medical treatment at home was provided. Those changes were most likely a results of spontaneous thrombolysis with subsequent recovery of coronary blood flow in infarct-related artery due to rarely occurring activation of fibrinolytic system. The fibrinolysis system was triggered by the release of plasminogen activator and affected newly formed thrombus. However unstable atherosclerotic plaque was thrombogenic enough and leaded to recurrence of myocardial infarction. Thus the patient received coronary artery stenting. Clinical and morphological data has shown that in those patients a major role in development of acute coronary syndrome plays not a coronary artery spasm but a coronary thrombosis with subsequent spontaneous thrombolysis and restoration of coronary blood flow which happened upon timely application of antiaggregants, anticoagulants and antianginals drugs. Coronary artery spasm typically occurs more distal from the obstruction place as a result of exposure to vasoconstrictors released after thrombocyte degranulation. Spontaneous thrombolysis by acute myocardial infarction is untypical, hence myocardial infarction with pathological Q wave develops.  Conclusions. Patients with acute coronary syndrome, which exhibit spontaneous thrombolysis require angiography and stenting of coronary arteries as soon as possible to prevent recurrence of coronary thrombosis and development of acute myocardial infarction.

Effect of Single-Level Transforaminal Lumbar Interbody Fusion on Segmental and Overall Lumbar Lordosis in Patients with Lumbar Degenerative Disease.

To investigate the ability of transforaminal lumbar interbody fusion (TLIF) to improve lumbar lordosis (LL). In this retrospective study, 92 patients undergoing single-level TLIF to treat lumbar degenerative disease were divided into a low back pain, radiculopathy, and neurogenic claudication group according to their symptoms. Preoperative and postoperative measures, including segmental LL, whole LL, pelvic incidence (PI), pelvic tilt, thoracic kyphosis, sagittal vertical axis, visual analog scale for back and leg pain, and Oswestry Disability Index, were used to evaluate radiographic and clinical outcomes. All clinical parameters were significantly improved after TLIF. There was no significant difference in any radiographic parameters in the low back pain group. In the radiculopathy and neurogenic claudication groups, all radiographic parameters were significantly changed after TLIF except for segmental LL and PI in both groups and pelvic tilt in the radiculopathy group. No statistically significant differences were found in improvement of segmental LL, PI, thoracic kyphosis, and visual analog scale (leg) between the radiculopathy and neurogenic claudication groups, whereas the differences in improvement of whole LL, pelvic tilt, PI-LL, sagittal vertical axis, visual analog scale (back), and Oswestry Disability Index were significant between the 2 groups. For patients with neurogenic leg symptoms owing to single-level lumbar degenerative disease, whole LL was improved after TLIF as a result of spontaneous restoration of lordosis at the unfused lumbar levels.

Influence of Afforestation on the Species Diversity of the Soil Seed Bank and Understory Vegetation in the Hill-Gullied Loess Plateau, China.

The Chinese Loess Plateau region has long been suffering from serious soil erosion. Thus, large-scale afforestation has continued during the past decades in order to control soil erosion. Afforestation can dramatically alter nutrient cycles, affect soil-carbon storage, and change hydrology. However, it is unknown how afforestation influences species diversity of the soil seed bank and understory vegetation compared with spontaneous restoration of abandoned land. Forest land with trees planted 30 years ago, abandoned slope land restored spontaneously for 30 years, and the corresponding slopes with remnant natural vegetation were selected as sampling sites. The species richness both in the soil seed bank and vegetation was significantly higher on the afforested slope compared to the spontaneously restored abandoned land. The species similarity between the afforested slope and the remnant slope land was high both in the soil seed bank and standing vegetation compared to the abandoned land. The soil seed bank density varied from 1778 ± 187 to 3896 ± 221 seeds/m2, and more than half of it was constituted by annual and biennial species, with no significant difference among sampling habitats. However, the afforested slope had higher seed density of grass and shrub/subshrubs compared to the abandoned slope. The present study indicates that in the study region, characterized by serious soil erosion, afforestation can better facilitate vegetation succession compared to spontaneously restoration of abandoned slope land.

Long-term net transformation and quantitative molecular mechanisms of soil nitrogen during natural vegetation recovery of abandoned farmland on the Loess Plateau of China

The availability of nitrogen (N) can alter vegetation species composition and diversity in degraded ecosystems. A comprehensive understanding of the dynamic fate of ammonium (NH4+-N) and nitrate (NO3−-N) processing and the underlying mechanisms are still lacking, particularly in arid to semi-arid degraded ecosystems. We compared and quantified the changes in the rates of net ammonification (Ra), nitrification (Rn) and total mineralization (Rm) and the abundance of bacteria, archaea, and microbial genes related to N transformation on the northern Loess Plateau of China across a 40-year chronosequence of farmland undergoing spontaneous restoration. We found that Ra, Rn, and Rm decreased in grassland soils (0–30-y sites) of different ages and exhibited significant increases at the 40-y sites. The capabilities of the soil to deliver NH4+-N and NO3−-N were not a limiting factor during the growing season after 40years of vegetation recovery. Soil mineral nitrogen may be not suitable for predicting and assessing the long-term (approximately 40years) restoration success and progress. The abundance of functional N genes showed differences in sensitivity to natural vegetation recovery of abandoned farmland, which likely reflects the fact that the multi-pathways driven by N functional microbial communities had a large influence on the dynamic fate of NH4+-N and NO3−-N. Quantitative response relationships between net N transformation rates and microbial genes related to N transformation were established, and these relationships confirmed that different N transformation processes were strongly linked with certain N functional genes, and collaboratively contributed to N transformation as vegetation recovery progressed. Specifically, Ra was controlled by AOA-amoA, AOB-amoA, and nxrA; Rn was governed by napA, narG, nirK, nirS, and nosZ; and Rm was controlled by nifH, apr, AOA-amoA, AOB-amoA, nirS, and nirK.

Changes in thyroid hormone concentrations during neonatal extracorporeal membrane oxygenation.

Thyroid hormone concentrations can be disturbed during critical illness. Our aim was to determine changes in thyroid hormone concentrations during neonatal extracorporeal membrane oxygenation (ECMO). We included 21 ECMO-treated neonates. Age-specific s.d. scores (SDS) of free and total thyroxine (FT4; TT4), reverse and total triiodothyronine (rT3; TT3), thyroid-stimulating hormone (TSH) and thyroxine-binding globulin (TBG) were determined at six fixed time-points. Data were analyzed using general linear models. At baseline, mean SDS FT4 (-0.78, 95% CI: -1.37 to -0.19), TT4 (-1.97, 95% CI: -2.76 to -1.18), TT3 (-0.88, 95% CI: -1.13 to -0.63), TSH (-2.14, 95% CI: -2.93 to -1.35) and TBG (-3.52, 95% CI: -4.55 to -2.50) were low with high mean SDS rT3 (0.53, 95% CI: 0.28 to 0.78). One hour after start ECMO, TT4, TSH and TBG had further declined; 12 h after start ECMO TT3 had declined (all P<0.05). After this decline, mean SDS TSH increased to the baseline level 12 h after start ECMO (-2.50, 95% CI: -3.22 to -1.79), and was higher than baseline 48 h after start ECMO (-0.56, 95% CI: -1.29 to 0.17). This TSH increase was followed by increases in TT4 and TT3. FT4 remained constant within the normal range during ECMO. Thyroid hormone concentrations before ECMO were suggestive of non-thyroidal illness syndrome (NTIS). During ECMO, increases in TSH, TT4 and TT3 after an initial decline possibly reflect spontaneous restoration of the hypothalamic-pituitary-thyroid axis. FT4 remained constant within the normal range. This suggests that thyroxine therapy is not required during ECMO.

Dynamics of insertion sequence element IS629 inactivation of verotoxin 2 genes in Escherichia coli O157:H7.

There are several anecdotal reports of insertion sequence (IS) element inactivation of verotoxin genes among enterohaemorrhagic Escherichia coli of the serotype O157:H7, a pathogen causing severe gastrointestinal disease in infected humans. These insertions can be expected to drastically reduce the virulence of the bacteria. IS element inactivation has been shown to be reversible in model systems, suggesting the possibility of spontaneous restoration of virulence. In this study, traditional and high-throughput sequencing was used to characterise three patterns of IS629 inactivation of verotoxin 2 genes in EHEC O157:H7, caused by insertion or insertion followed by partial deletion. At least one of the patterns of inactivation appears to have persisted several years among cattle O157:H7, indicating it has no major effect on fitness in the animal reservoir. Digital PCR was used to directly quantify the reversal rates of the insertional inactivation of a selected isolate under laboratory conditions. Inserts were found to be absent from in the order of 1/105 of individual genomes, with significantly higher loss frequencies observed in cultures under nutrient-poor conditions. We conclude that strains with this type of inactivation found in food or animal samples should be considered a threat to human health, and may pose a challenge for PCR-based detection methods.

Neuroplastic Changes Following Brain Ischemia and their Contribution to Stroke Recovery: Novel Approaches in Neurorehabilitation.

Ischemic damage to the brain triggers substantial reorganization of spared areas and pathways, which is associated with limited, spontaneous restoration of function. A better understanding of this plastic remodeling is crucial to develop more effective strategies for stroke rehabilitation. In this review article, we discuss advances in the comprehension of post-stroke network reorganization in patients and animal models. We first focus on rodent studies that have shed light on the mechanisms underlying neuronal remodeling in the perilesional area and contralesional hemisphere after motor cortex infarcts. Analysis of electrophysiological data has demonstrated brain-wide alterations in functional connectivity in both hemispheres, well beyond the infarcted area. We then illustrate the potential use of non-invasive brain stimulation (NIBS) techniques to boost recovery. We finally discuss rehabilitative protocols based on robotic devices as a tool to promote endogenous plasticity and functional restoration.

Symmetry-protected zero-mode laser with a tunable spatial profile

We propose to utilize symmetry-protected zero modes of a photonic lattice to realize a single-mode, fixed-frequency, and spatially tunable laser. These properties are the consequence of the underlying non-Hermitian particle-hole symmetry, with which the energy spectrum satisfies $\varepsilon_m=-\varepsilon_n^*$. Unlike in the Hermitian case, the symmetric phase of particle-hole symmetry is no longer restricted to $\varepsilon=0$ but extends along the imaginary-$\varepsilon$ axis, which is set by the single-cavity frequency and symmetry-protected against position and coupling disorder of the photonic lattice. By selectively pumping different cavities in the photonic lattice, we control the spontaneous symmetry restoration process, which provides a convenient method to tune the spatial profile of the laser without changing its frequency.

Microbiological Attributes of Soil Under Spontaneous Restoration

Microbiological Attributes of Soil Under Spontaneous Restoration

HYPERTHYROIDISM AND ATRIAL FIBRILLATION

Review on a problem of the development of atrial fibrillation in patients with thyrotoxicosis is presented. Thyrotoxicosis is one of the most frequent endocrine diseases, conceding only to a diabetes mellitus. The most frequent reasons of hyperthyroidism are Graves’ disease and functional thyroid autonomy. The authors give an analysis of data on the cardiac effects of thyrotoxicosis, features of heart remodeling under the influence of thyroid hyperfunction, prevalence of atrial fibrillation in thyrotoxicosis, depending on age, as well as the possibility of restoring sinus rhythm in the combination of these diseases. Particular attention is paid to the effect on the heart of subclinical thyrotoxicosis, which is defined as a dysfunction of the thyroid gland, characterized by low serum concentration of thyrotropin, normal values of free thyroxine and free triiodothyronine. Subclinical hyperthyroidism is also capable of causing heart remodeling and diastolic dysfunction. Prevalence of thyrotoxicosis in elderly people is higher in areas of iodine deficiency; it is relevant for our country due to the large territory of iodine deficiency. In elderly patients, the cardiac effects of thyrotoxicosis prevail in the clinical picture, that makes it difficult to diagnose endocrine disorders, and correction of thyrotoxicosis is critically important for the successful control of the heart rhythm. The article also discusses the problem of thyrotoxic cardiomyopathy, caused by the toxic effect of excess thyroid hormones: features of this heart disorder, factors affecting its formation, clinical significance and contribution to the development of rhythm disturbances. The greatest significance is the development of atrial fibrillation as a result of thyrotox-icosis in older patients who already have various cardiovascular diseases. Atrial fibrillation is the most frequent heart rhythm disorder in thyrotoxicosis. The main cause of arrhythmia in hyperthyroidism is the simultaneous existence of frequent focal impulses and circular motions of the excitation wave – the mechanism re-entry. Successful treatment of atrial fibrillation in patients with thyrotoxicosis is possible only when euthyroidism is achieved. In most cases, after the elimination of thyrotoxicosis, a spontaneous restoration of the sinus rhythm is observed. The chances of sinus rhythm restoration are lower in elderly patients with concomitant organic diseases of the myocardium or long-term atrial fibrillation. Moreover, even radically cured thyrotoxicosis leads to deterioration in the life prognosis.