For a fixed hyperbolic quadric in PG(3, q ), let (respectively , ) denote the set of all lines of PG(3, q ) which are external (respectively tangent, secant) with respect to . We characterize the minimum size blocking sets of PG(3, q ) with respect to each of the line sets , ∪ and ∪ .
A survey was conducted with the objective to study seagrass distribution, bed size and shoot density in different substrata of the South Andaman Islands. A total of 231 seagrass sites were observed during the study, in which a total of eight species were found. The South Andaman region exhibited the highest species diversity followed by Havelock, Little Andaman and Neil Islands. Eleven continuous seagrass bed were noted during the study which were confined to three different types of substrata: sand only; sand mixed with coral sand and coral rubble; sand mixed with mud. Thalassia hemprichii and Cymodocea rotundata were found in dense canopies and covered large areas associated with sand and coral rubble. Halophila beccarii showed moderate abundance in muddy substrata and Halodule spp. grew in fine sand. The highest shoot density was recorded at Haddo, followed by Vijaya Nagar and Chidyatapu, contributed mostly by Halodule spp. In general, seagrass diversity and distribution were mainly influenced by the percentage composition of sand. The authors recommend that the seagrass meadow of Haddo should be considered for conservation priority because of multiple anthropogenic pressures, such as sewage input, dumping of solid wastes on the shoreline and anchoring of boats.
A Bayesian approach using wavelet coefficient modeling is proposed for de-noising additive white Gaussian noise in medical magnetic resonance imaging (MRI). In a parallel acquisition process, the magnetic resonance image is affected by white Gaussian noise, which is additive in nature. A normal inverse Gaussian probability distribution function is taken for modeling the wavelet coefficients. A Bayesian approach is implemented for filtering the noisy wavelet coefficients. The maximum likelihood estimator and median absolute deviation estimator are used to find the signal parameters, signal variances, and noise variances of the distribution. The minimum mean square error estimator is used for estimating the true wavelet coefficients. The proposed method is simulated on MRI. Performance and image quality parameters show that the proposed method has the capability to reduce the noise more effectively than other state-of-the-art methods. The proposed method provides 8.83%, 2.02%, 6.61%, and 30.74% improvement in peak signal-to-noise ratio, structure similarity index, Pratt’s figure of merit, and Bhattacharyya coefficient, respectively, over existing well-accepted methods. The effectiveness of the proposed method is evaluated by using the mean squared difference (MSD) parameter. MSD shows the degree of dissimilarity and is 0.000324 for the proposed method, which is less than that of the other existing methods and proves the effectiveness of the proposed method. Experimental results show that the proposed method is capable of achieving better signal-to-noise ratio performance than other tested de-noising methods.
Mathematical model for an adiabatic tubular chemical reactor which processes an irreversible exothermic chemical reaction has been considered. For steady state solution for an adiabatic tubular chemical reactor, the model can be reduced to ordinary differential equation with a parameter in the boundary conditions. Again the ordinary differential equation has been converted into a Hammerstein integral equation which can be solved numerically. B-spline wavelet method has been developed to approximate the solution of Hammerstein integral equation. This method reduces the integral equation to a system of algebraic equations. The numerical results obtained by the present method have been compared with the available results.
LIS1 mutations cause lissencephaly (LIS), a severe developmental brain malformation. Much less is known about its role in the mature nervous system. LIS1 regulates the microtubule motor cytoplasmic dynein 1 (dynein), and as LIS1 and dynein are both expressed in the adult nervous system, Lis1 could potentially regulate dynein-dependent processes such as axonal transport. We therefore knocked out Lis1 in adult mice using tamoxifen-induced, Cre-ER-mediated recombination. When an actin promoter was used to drive Cre-ER expression (Act-Cre-ER), heterozygous Lis1 knockout (KO) caused no obvious change in viability or behavior, despite evidence of widespread recombination by a Cre reporter three weeks after tamoxifen exposure. In contrast, homozygous Lis1 KO caused the rapid onset of neurological symptoms in both male and female mice. One tamoxifen-dosing regimen caused prominent recombination in the midbrain/hindbrain, PNS, and cardiac/skeletal muscle within a week; these mice developed severe symptoms in that time frame and were killed. A different tamoxifen regimen resulted in delayed recombination in midbrain/hindbrain, but not in other tissues, and also delayed the onset of symptoms. This indicates that Lis1 loss in the midbrain/hindbrain causes the severe phenotype. In support of this, brainstem regions known to house cardiorespiratory centers showed signs of axonal dysfunction in KO animals. Transport defects, neurofilament (NF) alterations, and varicosities were observed in axons in cultured DRG neurons from KO animals. Because no symptoms were observed when a cardiac specific Cre-ER promoter was used, we propose a vital role for Lis1 in autonomic neurons and implicate defective axonal transport in the KO phenotype.
Nutrient restriction reprograms cellular signaling and metabolic network to shape cancer phenotype. Lactate dehydrogenase A ( LDHA ) has a key role in aerobic glycolysis (the Warburg effect) through regeneration of the electron acceptor NAD + and is widely regarded as a desirable target for cancer therapeutics. However, the mechanisms of cellular response and adaptation to LDHA inhibition remain largely unknown. Here, we show that LDHA activity supports serine and aspartate biosynthesis. Surprisingly, however, LDHA inhibition fails to impact human melanoma cell proliferation, survival, or tumor growth. Reduced intracellular serine and aspartate following LDHA inhibition engage GCN 2‐ ATF 4 signaling to initiate an expansive pro‐survival response. This includes the upregulation of glutamine transporter SLC 1A5 and glutamine uptake, with concomitant build‐up of essential amino acids, and mTORC 1 activation, to ameliorate the effects of LDHA inhibition. Tumors with low LDHA expression and melanoma patients acquiring resistance to MAPK signaling inhibitors, which target the Warburg effect, exhibit altered metabolic gene expression reminiscent of the ATF 4‐mediated survival signaling. ATF 4‐controlled survival mechanisms conferring synthetic vulnerability to the approaches targeting the Warburg effect offer efficacious therapeutic strategies.
Post‐translational modifications in intestinal epithelial cells ( IEC s) allow for precise control in intestinal homeostasis, the breakdown of which may precipitate the pathological damage and inflammation in inflammatory bowel disease. The O‐linked β‐N‐acetylglucosamine (O‐Glc NA c) modification on intracellular proteins controls diverse biological processes; however, its roles in intestinal homeostasis are still largely unexplored. Here, we found that levels of protein O‐Glc NA cylation and the expression of O‐Glc NA c transferase ( OGT ), the enzyme adding the O‐Glc NA c moiety, were reduced in IEC s in human IBD patients. Deletion of OGT specifically in IEC s resulted in disrupted epithelial barrier, microbial dysbiosis, Paneth cell dysfunction, and intestinal inflammation in mice. Using fecal microbiota transplantation in mice, we demonstrated that microbial dysbiosis although was insufficient to induce spontaneous inflammation but exacerbated chemical‐induced colitis. Paneth cell‐specific deletion of OGT led to Paneth cell dysfunction, which might predispose mice to chemical‐induced colitis. On the other hand, the augmentation of O‐Glc NA c signaling by inhibiting O‐Glc NA case, the enzyme removing O‐Glc NA cylation, alleviated chemical‐induced colitis. Our data reveal that protein O‐Glc NA cylation in IEC s controls key regulatory mechanisms to maintain mucosal homeostasis.
Most of the religions of the world are based on some fundamental moral principles of good conduct/virtues and prohibits its followers to do anything which is not good for the welfare of the society as a whole. This fundamental moral principal of good conduct, in Buddhism, is known as Pancha Shila (Five Precepts or Five Virtues). Pancha Shila is the basic assumption of moral activities for both households as well as for renunciates. It forms the actual practice of morality. Each time the precepts are upheld, the moral volitions are strengthened, until morality becomes a habitualtrait through the condition of repetition. For the smooth functioning of a society, every Buddhist has to follow the five moral precepts i.e. abstaining from killing, abstaining from stealing, abstaining from sexual misconduct, abstaining from falsehood, abstaining from taking intoxicants. Jainism, Christianity, Hinduism and Islam too accept such ethical codes with little modification. These are called cardinal virtues. Jaina concept of Pancha Mahavrata is very close to Buddhist concept of Pancha Shila. In Jainism these are; Ahimsa (Abstinence from all injury to life), Satyam (Abstinence from falsehood), Asteyam (Abstinence from stealing), Brahmacharyam (abstinence from self indulgence), Aparigraha (Abstinence from all attachment). Mahatma Gandhi too accepted these five cardinal virtues given by Jainism but he added two more in it which are; Fearlessness and Faith in God. The five precepts of Buddhism offers the moral conducts following which everyone can avoid evil deeds and can contribute in making this world a better world for present and future generations. The precept of abstaining from killing leads to the respect for other’s life. The precept of abstaining from stealing leads to the respect for other’s property. The precept of abstaining from sexual misconduct leads to the respect for one’s own dignity and dignity of other’s especially women. The precept of abstaining from falsehood leads to the respect for honesty. The precept of abstaining from taking alcohol leads to innumerable number of good qualities like respect for a clear mind, respect for modesty of other human beings, respect for money, respect for one’s own dignity, respect for other’s life and so on. The five precepts of Buddhism make a person disciplined, which is one of the most important ingredients for the development of overall personality of a person. A developing country cannot become a developed one unless its citizens are disciplined. If we analyze the five precepts given by Buddhism then, we find that the solution for most of world problems lies in it. If everyone follows five precepts then, I think this world will be transformed into a better place, a place where people have respects for other’s life and property, where everybody’s interest will be taken care of, where people will have an altruistic approach towards society. In short, this world can be transformed into a heaven.
Pharmacological studies have suggested hypothalamic phosphodiesterase-3B to mediate leptin and insulin action in regulation of energy homeostasis. Whereas Pde3b-null mice show altered energy homeostasis, it is unknown whether this is due to ablation of Pde3b in the hypothalamus. Thus, to address the functional significance of hypothalamic phosphodiesterase-3B, we used Pde3bflox/flox and Nkx2.1-Cre mice to generate Pde3b Nkx2.1KD mice that showed 50% reduction of phosphodiesterase-3B in the hypothalamus. To determine the effect of partial ablation of phosphodiesterase-3B in the hypothalamus on energy and glucose homeostasis, males and females were subjected to either a low- or high-fat diet for 19–21 weeks. Only female but not male Pde3b Nkx2.1KD mice on the low-fat diet showed increased body weight from 13 weeks onward with increased food intake, decreased fat pad weights and hypoleptinemia. Glucose tolerance was improved in high-fat diet-fed male Pde3b Nkx2.1KD mice in association with decreased phosphoenolpyruvate carboxykinase-1 and glucose-6-phosphatase mRNA levels in the liver. Also, insulin sensitivity was increased in male Pde3b Nkx2.1KD mice on the low-fat diet. Changes in body weight or in glucose homeostasis were not associated with any alteration in hypothalamic proopiomelanocortin, neuropepide Y and agouti-related peptide mRNA levels. These results suggest that partial loss of phosphodiesterase-3B in the hypothalamus produces a sex-specific response in body weight and glucose homeostasis, and support a role, at least in part, for hypothalamic phosphodiesterase-3B in regulation of energy and glucose homeostasis in mice.