The Connectivity of Boolean Satisfiability: Computational and Structural Dichotomies

Boolean satisfiability problems are an important benchmark for questions about complexity, algorithms, heuristics and threshold phenomena. Recent work on heuristics, and the satisfiability threshold has centered around the structure and connectivity of the solution space. Motivated by this work, we study structural and connectivity-related properties of the space of solutions of Boolean satisfiability problems and establish various dichotomies in Schaefer's framework. On the structural side, we obtain dichotomies for the kinds of subgraphs of the hypercube that can be induced by the solutions of Boolean formulas, as well as for the diameter of the connected components of the solution space. On the computational side, we establish dichotomy theorems for the complexity of the connectivity and st-connectivity questions for the graph of solutions of Boolean formulas. Our results assert that the intractable side of the computational dichotomies is PSPACE-complete, while the tractable side - which includes but is not limited to all problems with polynomial time algorithms for satisfiability - is in P for the st-connectivity question, and in coNP for the connectivity question. The diameter of components can be exponential for the PSPACE-complete cases, whereas in all other cases it is linear; thus, small diameter and tractability of the connectivity problems are remarkably aligned. The crux of our results is an expressibility theorem showing that in the tractable cases, the subgraphs induced by the solution space possess certain good structural properties, whereas in the intractable cases, the subgraphs can be arbitrary

The effect of molybdenum levels in sorghum (Sorghum vulgare Pers.) on uric acid and copper excretion in man

1. The effect of various dietary levels of molybdenum on uric acid and copper excretion was studied in experiments with four adult men given diets based on two sorghum varieties (Sorghum vulgare Pers.) differing widely in Mo content. 2. With a Mo intake of 160, 540 or 1540 µg/d the urinary excretion of uric acid was unaltered. 3. The excretion of Cu in urine increased with increasing Mo intake. 4. Cu-balance studied with high- and low-Mo diets showed that with a high-Mo diet urinary Cu excretion increased but faecal Cu was unaffected. This indicates that dietary Mo had no effect on Cu absorption. 5. The high serum concentration of Cu with diets high in Mo indicates that Mo either mobilizes tissue Cu or inhibits Cu uptake, or both

Fish protein concentrates in the treatment of kwashiorkor

Fifty-seven children suffering from kwashiorkor were hospitalized and given diets in which the major source of protein was from either fish protein concentrate (FPC) or skim milk. Diets containing fish protein concentrates were not well accepted by a large proportion of the children. In those who did consume it, both the clinical and biochemical responses compared favorably with those obtained in children receiving the diets containing skim milk, except for the increase in body weight after the disappearance of edema. Analysis of the cooked diets showed that the amounts of available lysine were lower in the FPC diets than in the skim milk diets. However, supplementation studies, using pure l-lysine, suggested that the lower gain in body weight could not be ascribed to this factor. Fish flour does not appear to be a satisfactory substitute for skim milk in the treatment of kwashiorkor, not only because of its non-acceptance by a large number of children but also because of its inability to promote body weight gains

Age of the Lower Vindhyan sediments, Central India

The basic issue raised by the two simultaneous and sensational reports in 1998 of body fossil evidence (worm tracks and small shelly fauna, respectively) of multicellular life in the Lower Vindhyan sediments, is the true age of the latter. Is the true age Mid-Proterozoic as believed so far, on limited geochronological data and assumed by Seilacher et al.? Or is it only Early Cambrian, as was argued by Azmi and supported by a single preliminary Ar-Ar age of 617 Ma measured soon after the reports? Although both the fossil evidences are now equivocal, the basic issue remains. We report consistent Rb-Sr ages for glauconies from the Lower Vindhyan sediments (Semri Group) near Chitrakut, which constrain the onset of the earliest Vindhyan sedimentation to not later than 1600 Ma. Considering other available chronological constraints, the Vindhyan basin is likely to preserve a rare, very long and least disturbed record of Pre-cambrian sedimentation

Kwashiorkor and mental development

Nineteen children successfully treated for kwashiorkor were followed up to see the effect of early malnutrition on growth and mental functions. These children were compared with appropriately matched controls selected from the same locality and the school from which the experimental children were derived. These controls were matched for age, sex, religion, caste, socioeconomic status, family size, birth order, and educational level of the parents and the subjects. Suitable intelligence tests and sensory development tests were constructed and these tests were applied to both the experimental and control groups of children. In addition to these tests, anthropometric measurements were also taken on all children. The salient features of the study are: a) There was a significant difference between the performance of the control and the experimental subjects with regard to the intelligence tests. This difference was particularly marked in the younger age group (8-9 years) and tended to diminish in the older age group (10-11 years). b) Intersensory organization was poorer in the experimental subjects than in the control subjects. The performance in the intersensory tests was markedly poorer in the younger age group and tended to improve in the older age group (10-11 years). c) The retardation was noticeable mainly with regard to perceptual and abstract abilities

Biochemical changes in the skin in kwashiorkor

The total nitrogen, dermal nitrogen, and collagen nitrogen content of the skin and the amino acid pattern of the dermis were determined in the skin obtained from 10 normal children and in 19 children suffering from kwashiorkor, 7 of whom had characteristic cutaneous lesions. The skin of children with kwashiorkor had lower levels of total nitrogen, dermal nitrogen, and collagen nitrogen compared with normal children, and the reduction in all these components was of a greater magnitude in children who had cutaneous lesions. There was a significant reduction in the hydroxyproline content of the dermis in all children and a rise in the arginine and ammonia content. In the dermis of children with cutaneous lesions, hydroxyproline, tyrosine, proline, and glycine levels were lowered. These findings provide a biochemical explanation for the occurrence of cutaneous lesions in kwashiorkor

Remote Sensing Data Visualization, Fusion and Analysis via Giovanni

We describe Giovanni, the NASA Goddard developed online visualization and analysis tool that allows users explore various phenomena without learning remote sensing data formats and downloading voluminous data. Using MODIS aerosol data as an example, we formulate an approach to the data fusion for Giovanni to further enrich online multi-sensor remote sensing data comparison and analysis

Study on Esthetic Appearance of Reconstructed Pinna in Microtia

INTRODUCTION: Microtia is a cogenital malformation characterized by total or partial absence of the whole auricle or any of its components, varying from a small auricle to total absence (Anotia). Microtia is the most common congenital anomaly of auricle. Reconstruction of the microtia ear represents one of the most demanding challenges in reconstructive surgery. Total auricular reconstruction with autogenous costal cartilage is one of the greatest technical feats that a reconstructive surgeon may encounter. An inherent understanding of sculpture and design influence the success of surgery. In this study we had followed Dr. Brent four stage pinna reconstruction techniques and we had analysised ethestic appearance pinna reconstruction in fifteen cases. AIM AND OBJECTIVE OF THE STUDY: To study on esthetic component of reconstructed of pinna in our microtia cases. To create an acceptable facsimile of an ear of the proper size, position and orientation to other facial features. MATERIAL AND METHODS: The present the study on esthetic appearance of reconstructed pinna in microtia was done in the Department of Plastic, Reconstructive and Facio- Maxillary surgery, Madras Medical College and Hospital, Chennai during July 2003 to June 2005 and all the cases were regularly followed up in the outpatient department of plastic surgery at 2 months intervals upto August 2005. Inclusion criteria are 1. Microtia type II A and Type II – B (Tanzer classification), 2. Either Sex, 3. Age group 6 years to 30 years. Exclusion Criteria are 1. Microtia associated with syndrome (Treacher Collin Syndrome, Hemifacial Microsomia), 2. Age below 6 years and above 30 years. RESULTS: The present study consisted of fifteen cases of microtia II A (complete hypoplasia auricle with absence external auditory canal). All patients had undergone four stage pinna reconstruction in the department of plastic surgery July 2003 to August 2005. SUMMARY AND CONCLUSION: Management of microtia can be one of the most rewarding yet humbling challenges faced by the reconstructive surgreon. For 15 case microtia type – A we had followed total auricular reconstruction is with autologous cartilage and on modification of the methods of Brent. Our goals in auricular reconstruction of microtia are i) A satisfied patient, ii) proper positioning, iii) a pleasing size and contour. In ear reconstruction should be an ear that is sufficiently natural in appearance it will pass unnoticed by others. Current methods fall short of this goal, however, because of the transplanted autologous tissue, which are different from those in the normal ear. Even if perfect framework could be carved from costal cartilage, the ideal ear would still elude use because the thicker temporal mastoid skin would obscure the delicacy of the convolution what we have achieved as highly pointed out by the BRENT “An acceptable facsimile of ear” which is happily accepted by our patients and parents. As pointed out in our study, we have found out the caveats in the reconstruction of ear in our microtia patients. They are (1) The skin in the auriculomastoid area thicker on par with neck skin. (2) The amount fibrosis in the bed is also more in spite of adequate hemostasis and sharp and gentle dissection. (3) Cartilage volume available for framework is also relatively less. Because of the above reasons the delicate carving of the fabricated costal cartilage framework is obscured and therefore the interhelicine groove and fossa on the external aspect are less pronounced. To conclude that the highly complex nature of ear reconstruction places it in the higher echelons of reconstructive surgical procedures. The multidisciplinary issue surrounding congenital ear deformities. Combined with the technical expertise and experience necessary to satisfactorily conduct the surgery, suggest that these types of reconstruction should not he performed by surgeons unfamiliar with the technique optimal results can be only achieved through dedicated study and experience

Prevalence of Major Depressive Disorder among Mothers of Children and Adolescents with Attention Deficit Hyperactivity Disorder Attending a Tertiary Care Centre

Abstract                                      Introduction : Attention deficit hyperactivity disorder (ADHD) accounts for the majority of referrals to child and adolescent psychiatry services because of the associated poor scholastic performance. Despite the possibility of depressive symptoms in caregivers, there is a paucity of studies on major depressive disorder among mothers of children and adolescents with ADHD in our setting   Objectives : Assessing the prevalence of major depressive disorder and the association of sociodemographic and clinical variables among mothers of children & adolescents with ADHD attending a tertiary care centre. Studying the correlation between the severity of ADHD and maternal depression.   Methods: Cross-sectional study on 150 mothers of children and adolescents aged 5-18 years with ADHD attending the Child and Adolescent Psychiatry Clinic of the Govt. Medical College, Thiruvananthapuram.   Results : The  prevalence of Major Depressive Disorder among mothers belonging to the age group of 30‒39 years was found to be 20%. Across age groups, 28.7% of the subjects had minimal depressive symptoms, while 10% each had mild and moderate symptoms. We found a positive correlation between the severity of maternal depression and the child’s ADHD. The association of major depressive disorder with medical comorbidities and having another offspring with ADHD was statistically significant.   Conclusion: Owing to the statistically high prevalence of depressive disorders, routine screening for the depressive symptoms has to be considered for mothers when the children are diagnosed with ADHD, with the provision for appropriate intervention.   Keywords: Attention Deficit Hyperactivity Disorder; Major Depressive Disorder, Scholastic performance, Sociodemographic and clinical variables,     &nbsp

Hypocholesteremic effect of phenoxybenzamine (Dibenzyline), an adrenergic blocking agent: experimental studies with monkeys and human volunteers

The effect of an orally effective adrenergic blocking agent, Dibenzyline, on serum cholesterol levels was studied in human subjects and in monkeys on high-fat diets. In addition, the effect of the phenoxyethyl analogue of Dibenzyline, G-D 131, was also investigated in monkeys. The studies showed that the increase in serum cholesterol level brought about by a high-fat diet in monkeys could be considerably reduced by supplementation with Dibenzyline. This hypocholesteremic action was also observed with the analogue of Dibenzyline, G-D 131, which does not possess the adrenergic blocking property. It appears, therefore, that the hypocholesteremic action of Dibenzyline is independent of its adrenergic blocking activity. When a high-fat diet which also contained a high amount of cholesterol was used, Dibenzyline retarded the increase in serum cholesterol of monkeys for a considerable length of time. Administration of Dibenzyline, 10 mg. daily for 11 days, brought about a fall in serum cholesterol in two of the three human subjects and arrested the further increase in serum cholesterol in the third subject on a high-butterfat diet. All the subjects showed increased fecal elimination of cholic and dihydroxycholanic acids during the Dibenzyline-supplemented period, suggesting that the hypocholesteremic effect of the drug is at least partly mediated through increased elimination of cholesterol as bile acids