Counterterm Method in Lovelock Theory and Horizonless Solutions in Dimensionally Continued Gravity

In this paper we, first, generalize the quasilocal definition of the stress energy tensor of Einstein gravity to the case of Lovelock gravity, by introducing the tensorial form of surface terms that make the action well-defined. We also introduce the boundary counterterm that removes the divergences of the action and the conserved quantities of the solutions of Lovelock gravity with flat boundary at constant $t$ and $r$. Second, we obtain the metric of spacetimes generated by brane sources in dimensionally continued gravity through the use of Hamiltonian formalism, and show that these solutions have no curvature singularity and no horizons, but have conic singularity. We show that these asymptotically AdS spacetimes which contain two fundamental constants are complete. Finally we compute the conserved quantities of these solutions through the use of the counterterm method introduced in the first part of the paper.Comment: 15 pages, references added, typos correcte

Acid-modified Biochar Effect on Some Physiological Indicators and Micronutrient Availability of Quinoa (cv. Gizavan) in a Calcareous Soil

Introduction Organic matter and alkaline pH are the main causes of nutrient deficiencies in calcareous soils of arid and semi-arid regions. The availability of some nutritional elements, including the micronutrients such as iron, zinc, copper, and manganese is very low in calcareous soils, although the total concentration of these elements may be relatively high.  Burning crop residues results in substantial loss of nutrients, and may lead to air pollution and human health problems. An alternative approach is to apply crop residues to soil in the form of biochar. The biochar modification with acid may increase the solubility of nutrients (P, Fe, Zn, Cu, Mn) present in biochar, thereby significant improvement in mineral nutrition of plants grown in calcareous soils. Therefore, the object of this study is to investigate the effect of acid-modified biochar from rice residues on the amount of chlorophyll and the micronutrient concentration of quinoa plant (Chenopodium quinoa) in a calcareous soil.   Methods and Materials The soil was air-dried and ground to pass through a 2-mm sieve then was analyzed to determine various soil physico-chemical properties using standard methods. To achieve the aim of this study the factorial experiment was carried out based on a completely randomized design in 4 replications. Factors include 3 types of biochar (unmodified, modified by pre-acidic method and modified by post-acidic method) and different levels of biochar (0, 2, and 5% by weight). Then 10 quinoa seeds were planted in each pot at 2-cm depth which after emergence, declined to 3 plants in each pot. The pots were randomly moved twice a week during the growth period to eliminate environmental effects. Irrigation and weeding operations were performed by hand. Determination of chlorophyll content (a, b, and ab) and carotenoids were measured precisely before harvesting in fresh plants using Arnon method.  Plants were harvested at 187 days after planting, washed with distilled water and dry with tissue paper. The samples were air-dried and then oven dried at 65˚C to a constant weight in a forced air-driven oven. Then the total micronutrient content of the plant was determined after dry ashing. The statistical results of the data were analyzed using SAS software (9.4) and LSD test (at 5% level) was used for comparing the mean values.   Results and Discussion Based on the variance analysis, all attributes responded positively to different types and levels of biochar and modified biochar (p<0.01). The comparison of the average effect of the studied treatments showed that with the increase in the levels of all three types of biochar, the amount of chlorophyll a, b, total, and carotenoid increased so the highest amount of chlorophyll a, b, total, and carotenoid respectively, with an average of 2.58 and 1.54, 4.13 and 1.36 mg g-1 were obtained from the treatment of 5% post-acidic biochar. The results showed that the highest amount of Fe concentration in shoots with an average of 229.48 mg kg-1 was obtained from the treatment of 5% post-acidic biochar, although there was no statistically significant difference with the treatment of 5% pre-acidic biochar with an average of 220.48 mg kg-1 and its lowest value with an average of 95.95 mg kg-1 was related to unmodified biochar. The highest amount of Zn concentration in shoots with an average of 13.42 mg kg-1 was related to the treatment of 5% post-acidic biochar which showed an increase of 13.24 and 33.26% compared to the treatment of 5% pre-acidic and unmodified biochar, respectively. Also, the highest concentrations of Cu and Mn in shoots were obtained with an average of 3.85 and 23.37 mg kg-1 respectively, from the treatment of 5% post-acidic biochar.   Conclusion Post-acidic biochar had better results in terms of physiological indices and the concentration of micronutrients (Fe, Zn, Cu, and Mn) than unmodified biochar in quinoa. The increase of nutrients in quinoa can be attributed to the dissolution of biochar nutrients after being modified with acid and the reduction of pH and the availability of these elements in the soil. Therefore, biochar modified with acid or biochar produced from sources that have acidic properties can be recommended as a suitable method for improving fertility and increasing micronutrients in calcareous soils affected by salt

Coronavirus disease 2019 (COVID-19) can predispose young to Intracerebral hemorrhage: a retrospective observational study

Background: The respiratory system involvement is the most common presentation of Coronavirus disease 2019 (COVID-19). However, other organs including the central nervous system (CNS) could be affected by the virus. Strokes, seizures, change in mental status, and encephalitis have been reported as the neurological manifestation of the disease. We hypothesized that COVID-19 could predispose younger patients to spontaneous intracerebral hemorrhage (ICH). The present study aimed to investigate whether COVID-19 has any relationship with the occurrence of spontaneous ICH in young or not. Methods: We retrospectively evaluated all the patients with spontaneous ICH who were referred to our center between 20 Feb and 1 Sep 2020. The demographic, clinical, radiological, and laboratory test data were evaluated. Patients were divided into two groups. The COVID-19 positive patients and COVID-19 negative ones. All the variables including age, sex, history of hypertension, diabetes mellitus, smoking, Glasgow Coma Scale (GCS), hematoma volume and location, the presence of intraventricular hemorrhage and hydrocephalus on admission, the length of hospital stay, the lab test results and the clinical outcome at last visit or discharge as Glasgow Outcome Scale (GOS) were compared between the two groups. Results: There were 22 COVID-19 positive patients (20.8%) and 84 COVID-19 negative ones (79.2%). The mean age of the patients in the case group (54.27 ± 4.67) was significantly lower than that in the control group (69.88 ± 4.47) (p \u3c 0.05). Meanwhile, our results showed a significant difference between the two groups based on the presence of chronic arterial hypertension (p \u3c 0.05). There were no significant differences between the two groups based on gender, diabetes mellitus, smoking, Glasgow Coma Scale (GCS), hematoma volume, need for surgery, the presence of intraventricular hemorrhage and hydrocephalus on admission, White Blood Cell (WBC) count, platelet count, Prothrombin Time (PT), and Partial Thromboplastin Time (PTT) (p \u3e 0.05). Conclusions: Our results show that COVID positive patients with ICH are younger and with less predisposing factors than COVID negative subjects with ICH

Perlecan is critical for heart stability

Perlecan is a heparansulfate proteoglycan found in basement membranes, cartilage, and several mesenchymal tissues that form during development, tumour growth, and tissue repair. Loss-of-function mutations in the perlecan gene in mice are associated with embryonic lethality caused primarily by cardiac abnormalities probably due to hemopericards. The aim of the present study was to investigate the mechanism underlying the early embryonic lethality and the pathophysiological relevance of perlecan for heart function. Perlecan-deficient murine embryonic stem cells were used to investigate the myofibrillar network and the electrophysiological properties of single cardiomyocytes. The mechanical stability of the developing perlecan-deficient mouse hearts was analysed by microinjecting fluorescent-labelled dextran. Maturation and formation of basement membranes and cell-cell contacts were investigated by electron microscopy, immunohistochemistry, and western blotting. Sarcomere formation and cellular functional properties were unaffected in perlecan-deficient cardiomyocytes. However, the intraventricular dye injection experiments revealed mechanical instability of the early embryonic mouse heart muscle wall before embryonic day 10.5 (E10.5). Accordingly, perlecan-null embryonic hearts contained lower amounts of the critical basement membrane components, collagen IV and laminins. Furthermore, basement membranes were absent in perlecan-null cardiomoycytes whereas adherens junctions formed and matured around E9.5. Infarcted hearts from perlecan heterozygous mice displayed reduced heart function when compared with wild-type hearts. We propose that perlecan plays an important role in maintaining the integrity during cardiac development and is important for heart function in the adult heart after injury