A new logistic growth model applied to COVID-19 fatality data.

BACKGROUND: Recent work showed that the temporal growth of the novel coronavirus disease (COVID-19) follows a sub-exponential power-law scaling whenever effective control interventions are in place. Taking this into consideration, we present a new phenomenological logistic model that is well-suited for such power-law epidemic growth. METHODS: We empirically develop the logistic growth model using simple scaling arguments, known boundary conditions and a comparison with available data from four countries, Belgium, China, Denmark and Germany, where (arguably) effective containment measures were put in place during the first wave of the pandemic. A non-linear least-squares minimization algorithm is used to map the parameter space and make optimal predictions. RESULTS: Unlike other logistic growth models, our presented model is shown to consistently make accurate predictions of peak heights, peak locations and cumulative saturation values for incomplete epidemic growth curves. We further show that the power-law growth model also works reasonably well when containment and lock down strategies are not as stringent as they were during the first wave of infections in 2020. On the basis of this agreement, the model was used to forecast COVID-19 fatalities for the third wave in South Africa, which was in progress during the time of this work. CONCLUSION: We anticipate that our presented model will be useful for a similar forecasting of COVID-19 induced infections/deaths in other regions as well as other cases of infectious disease outbreaks, particularly when power-law scaling is observed.

Biogenic link to the recent increase in atmospheric methane over India.

Methane (CH4) is a prominent Greenhouse Gas (GHG) and its global atmospheric concentration has increased significantly since the year 2007. Anthropogenic CH4 emissions are projected to be 9390 million metric tonnes by 2020. Here, we present the long-term changes in atmospheric methane over India and suggest possible alternatives to reduce soil emissions from paddy fields. The increase in atmospheric CH4 concentrations from 2009 to 2020 in India is significant, about 0.0765 ppm/decade. The Indo-Gangetic Plains, Peninsular India and Central India show about 0.075, 0.076 and 0.074 ppm/decade, respectively, in 2009-2020. Seasonal variations in CH4 emissions depend mostly on agricultural activities and meteorology, and contribution during the agricultural intensive period of Kharif-Rabi (i.e., June-December) is substantial in this regard. The primary reason for agricultural soil emissions is the application of chemical fertilizers to improve crop yield. However, for rice farming, soil amendments involving stable forms of carbon can reduce GHG emissions and improve soil carbon status. High crop production in pot culture experiment resulted in lower potential yield-scaled GHG emissions in rice with biochar supplement. The human impact of global warming induced by agricultural activities could be reduced by using biochar as a natural solution.

Record high levels of atmospheric ammonia over India: Spatial and temporal analyses.

Atmospheric ammonia (NH3) is an alkaline gas and a prominent constituent of the nitrogen cycle that adversely affects ecosystems at higher concentrations. It is a pollutant, which influences all three spheres such as haze formation in the atmosphere, soil acidification in the lithosphere, and eutrophication in water bodies. Atmospheric NH3 reacts with sulfur (SOx) and nitrogen (NOx) oxides to form aerosols, which eventually affect human health and climate. Here, we present the seasonal and inter-annual variability of atmospheric NH3 over India in 2008-2016 using the IASI (Infrared Atmospheric Sounding Interferometer) satellite observations. We find that Indo-Gangetic Plains (IGP) is one of the largest and rapidly growing NH3 hotspots of the world, with a growth rate of +1.2% yr-1 in summer (June-August: Kharif season), due to intense agricultural activities and presence of many fertilizer industries there. However, our analyses show insignificant decreasing trends in annual NH3 of about -0.8% yr-1 in all India, about -0.4% yr-1 in IGP, and -1.0% yr-1 in the rest of India. Ammonia is positively correlated with total fertilizer consumption (r = 0.75) and temperature (r = 0.5) since high temperature favors volatilization, and is anti-correlated with total precipitation (r = from -0.2, but -0.8 in the Rabi season: October-February) as wet deposition helps removal of atmospheric NH3. This study, henceforth, suggests the need for better fertilization practices and viable strategies to curb emissions, to alleviate the adverse health effects and negative impacts on the ecosystem in the region. On the other hand, the overall decreasing trend in atmospheric NH3 over India shows the positive actions, and commitment to the national missions and action plans to reduce atmospheric pollution and changes in climate.

Marker-assisted pyramiding of Thinopyrum-derived leaf rust resistance genes Lr19 and Lr24 in bread wheat variety HD2733.

This study was undertaken to pyramid two effective leaf rust resistance genes (Lr19 and Lr24) derived from Thinopyrum (syn. Agropyron), in the susceptible, but agronomically superior wheat cultivar HD2733 using marker-assisted selection. In the year 2001, HD2733 was released for irrigated timely sown conditions of the north eastern plains zone (NEPZ) of India became susceptible to leaf rust, a major disease of the region. Background selection helped in developing near-isogenic lines (NILs) of HD2733 with Lr19 and Lr24 with 97.27 and 98.94%, respectively, of genomic similarity with the parent cultivar, after two backcrossing and one generation of selfing.NILs were intercrossed to combine the genes Lr19 and Lr24. The combination of these two genes in the cultivar HD2733 is expected to provide durable leaf rust resistance in farmers' fields.

A novel interaction between the FLJ33534 locus and smoking in obesity: a genome-wide study of 14 131 Pakistani adults.

BACKGROUND: Obesity is a complex disease caused by the interplay of genetic and lifestyle factors, but identification of gene-lifestyle interactions in obesity has remained challenging. Few large-scale studies have reported use of genome-wide approaches to investigate gene-lifestyle interactions in obesity. METHODS: In the Pakistan Risk of Myocardial Infraction Study, a cross-sectional study based in Pakistan, we calculated body mass index (BMI) variance estimates (square of the residual of inverse-normal transformed BMI z-score) in 14 131 participants and conducted genome-wide heterogeneity of variance analyses (GWHVA) for this outcome. All analyses were adjusted for age, age(2), sex and genetic ancestry. RESULTS: The GWHVA analyses identified an intronic variant, rs140133294, in the FLJ33544 gene in association with BMI variance (P-value=3.1 × 10(-8)). In explicit tests of gene × lifestyle interaction, smoking was found to significantly modify the effect of rs140133294 on BMI (Pinteraction=0.0005), whereby the minor allele (T) was associated with lower BMI in current smokers, while positively associated with BMI in never smokers. Analyses of ENCODE data at the FLJ33534 locus revealed features indicative of open chromatin and high confidence DNA-binding motifs for several transcription factors, providing suggestive biological support for a mechanism of interaction. CONCLUSIONS: In summary, we have identified a novel interaction between smoking and variation at the FLJ33534 locus in relation to BMI in people from Pakistan.

Genetic diversity analysis of Zingiber Officinale Roscoe by RAPD collected from subcontinent of India.

The present investigation was undertaken for the assessment of 12 accessions of Zingiber officinale Rosc. collected from subcontinent of India by RAPD markers. DNA was isolated using CTAB method. Thirteen out of twenty primers screened were informative and produced 275 amplification products, among which 261 products (94.90%) were found to be polymorphic. The percentage polymorphism of all 12 accessions ranged from 88.23% to 100%. Most of the RAPD markers studied showed different levels of genetic polymorphism. The data of 275 RAPD bands were used to generate Jaccard's similarity coefficients and to construct a dendrogram by means of UPGMA. Results showed that ginger undergoes genetic variation due to a wide range of ecological conditions. This investigation was an understanding of genetic variation within the accessions. It will also provide an important input into determining resourceful management strategies and help to breeders for ginger improvement program.

Nano-vectors for the Ocular Delivery of Nucleic Acid-based Therapeutics.

Nucleic acid-based therapeutics have gained a lot of interest for the treatment of diverse ophthalmic pathologies. The first to enter in clinic has been an oligonucleotide, Vitravene(®) for the treatment of cytomegalovirus infection. More recently, research on aptamers for the treatment of age related macular degeneration has led to the development of Macugen(®). Despite intense potential, effective ocular delivery of nucleic acids is a major challenge since therapeutic targets for nucleic acid-based drugs are mainly located in the posterior eye segment, requiring repeated invasive administration. Of late, nanotechnology-based nano-vectors have been developed in order to overcome the drawbacks of viral and other non-viral vectors. The diversity of nano-vectors allows for ease of use, flexibility in application, low-cost of production, higher transfection efficiency and enhanced genomic safety. Using nano-vector strategies, nucleic acids can be delivered either encapsulated or complexed with cationic lipids, polymers or peptides forming sustained release systems, which can be tailored according to the ocular tissue being targeted. The present review focuses on developments and advances in various nano-vectors for the ocular delivery of nucleic acid-based therapeutics, the barriers that such delivery systems face and methods to overcome them.

Enhanced production of SCL-LCL-PHA co-polymer by sludge-isolated Pseudomonas aeruginosa MTCC 7925.

AIM: To boost short-chain-length-long-chain-length polyhydroxyalkanoate (SCL-LCL-PHA) co-polymer yield in Pseudomonas aeruginosa MTCC 7925 by manipulating culture conditions. METHODS AND RESULTS: Stationary phase culture of P. aeruginosa MTCC 7925 was subjected to various doses of different carbons and, N and P deficiencies. Enhanced co-polymer yield was recorded under ethanol- and glucose-supplemented cultures. Interaction of ethanol with N-deficiency boosted co-polymer accumulation maximally. CONCLUSIONS: The sludge-isolated P. aeruginosa MTCC 7925 demonstrated good capability to synthesize SCL-LCL-PHA co-polymer from unrelated carbon sources. Supplementation of ethanol under N-deficiency boosted the co-polymer yield up to 69% of dry cell weight, which is significantly higher when compared with other SCL-MCL-PHA co-polymer accumulating bacterial species. SIGNIFICANCE AND IMPORTANCE OF THE STUDY: This is the first report on P. aeruginosa MTCC 7925, which is capable of accumulating LCL 3-hydroxyhexadecanoate and 3-hydroxyoctadecanoate units with SCL 3-hydroxybutyrate and 3-hydroxyvalerate as constituents of PHAs. This opens up new possibilities for various industrial applications owing to the superior properties of this new co-polymer.

Discrepancy between subcritical and fast rupture roughness: a cumulant analysis.

Rough crack fronts in a sheet of paper, obtained during a creep experiment, do not follow true scaling laws. Local roughness exponents are estimated using the first order cumulant, a quantity recently introduced in the turbulence literature [J. Delour, J. F. Muzy, and A. Arneodo, Eur. Phys. J. B 23, 243 (2001)10.1007/s100510170074]. Using a large data set (102 fronts), we find a significant difference in local roughness between the slow (subcritical) and the fast growth regime.

Enhanced poly-beta-hydroxybutyrate accumulation in a unicellular cyanobacterium, Synechocystis sp. PCC 6803.

AIM: To stimulate poly-beta-hydroxybutyrate (PHB) accumulation in Synechocystis sp. PCC 6803 by manipulating culture conditions. METHODS AND RESULTS: Stationary phase cultures of Synechocystis sp. PCC 6803 were subjected to N- and P-deficiency, chemoheterotrophy and limitations of gas-exchange. Enhanced PHB accumulation was observed under all the above conditions. However, interaction of P-deficiency with gas-exchange limitation (GEL) in the presence of exogenous carbon boosted PHB accumulation maximally. CONCLUSIONS: Combined effects of P-deficiency and GEL boosted PHB accumulation up to 38% (w/w) of dry cell weight (dcw) in Synechocystis sp. PCC 6803 in the presence of fructose and acetate. This value is about eightfold higher as compared with the accumulation under photoautotrophic growth condition. SIGNIFICANCE AND IMPORTANCE OF THE STUDY: These results showed a good potential of Synechocystis sp. PCC 6803 in accumulating poly-beta-hydroxybutyrate, an appropriate raw material for biodegradable and biocompatible plastic. Poly-beta-hydroxybutyrate could be an important material for plastic and pharmaceutical industries.

Vancomycin anaphylaxis in a patient with vancomycin-induced red man syndrome.

Vancomycin is a powerful glycopeptide antibiotic that is increasingly being used owing to the emergence of highly resistant organisms such as methicillin-resistant Staphylococcus aureus. Although a generally safe medication, administration of vancomycin is not benign, and there have been a number of adverse reactions reported. We present the case of a patient with vancomycin-induced red man syndrome who developed vancomycin anaphylaxis. Our case illustrates that red man syndrome may be a marker for true vancomycin allergy, although it was generally not thought of as so in the past.

Studies on nitric oxide (NO) formation by the green alga Scenedesmus obliquus and the diazotrophic cyanobacterium Anabaena doliolum.

This study provides preliminary evidence that NO production could be a general attribute of algae. Anabaena doliolum was found to be a better NO producer than Scenedesmus and Synechoccocus. Experiments conducted with inhibitors of photosynthesis (DCMU), ATP synthesis (DCCD), and the uncoupler (2,4-DNP) and its analog arsenate clearly revealed that inhibition of nitrite assimilation through the blockage of nitrite reductase (NiR) is primarily responsible for NO emission. A linear relationship between nitrite concentration in the culture medium and NO in the exhaust gas supports the view that accumulation of nitrite is responsible for NO formation. A failure of Scenedesmus, grown in the medium substituted with W for Mo, to produce either NO/NO-2 in light or a 'light-off' peak, and a resumption of these activities upon the addition of Mo proved beyond doubt that a functional nitrate reductase (NR) is necessary for the production of nitrite and NO by algae grown on nitrate as the nitrogen source. Moreover, the appearance of a NO peak immediately after nitrite supplementation under dark conditions in W-substituted cultures with or without glucose ruled out an enzymatic role of NR in NO emission.

Peritoneal dialysis.

Peritoneal dialysis has now become an established form of renal replacement therapy; nearly half the patients on dialysis in the UK are treated in this way. Survival of patients is now equal to that with haemodialysis. However, long-term peritoneal dialysis (>8 years) is limited to a small percentage of patients because of dropout to haemodialysis for inherent complications of peritoneal dialysis--peritonitis, peritoneal access, inadequate dialysis, and patient-related factors. However, improvements in the understanding of the pathophysiological processes involving the peritoneal membrane have paved the way for advances in the delivery of adequate dialysis, more biocompatible dialysis fluids, and automated peritoneal dialysis. Other technical advances have led to a reduction in peritonitis. Peritoneal dialysis is an important dialysis modality and should be used as an integral part of RRT programmes.

Haemodialysis.

This paper charts the development of haemodialysis, the cornerstone of renal replacement therapy (RRT). It has enabled patients with end-stage renal failure to survive for years, in many cases with a surprisingly good quality of life. Through technological advances, RRT can be offered to patients who are older and more frail. Many have intercurrent comorbid illness. Such patients can have good quality of life, but their survival is shorter since they are likely to succumb early to comorbid illnesses. The challenge to nephrologists is to provide treatment based on exacting standards for all those patients who can benefit, yet to maintain cost-effectiveness. There is increasing recognition that, however good the technology underpinning dialysis, what justifies the cost and commitment that dialysis entails is the provision for the patient of a satisfactory quality of life.

Renal impairment in myeloma: time for a reappraisal?

It is generally considered that a patient with myeloma who also has established renal impairment is unlikely to do well. While this is sometimes the case, analysis of recent data shows: (a) of 2768 patients in the MRC database for the fourth to the sixth trials, 10/163 with serum creatinine 300-600 microm/l and 20/89 with serum creatinine 600 micro/l at presentation had renal failure as a recorded presenting feature, whatever the renal function, the most common presenting feature was bone pain; (b) that many patients have persisting evidence of reduced renal function yet survive for more than the median time of 36 months which applies to myeloma generally. Patients with renal impairment, especially those whose myeloma is brought to plateau by chemotherapy, should be assessed thoroughly for evidence of other than myeloma induced renal damage as both renovascular disease and prostatic obstruction in males are common in the elderly population at risk.

Cost of renal replacement therapy.

Renal replacement therapy (RRT) now sustains an older, medically complicated population, reducing dependency on haemodialysis. Costing focuses on avoidable treatment costs, e.g. late referral for management and inappropriate placement on a RRT modality because of restricted local options. Sound regional plans need to be implemented so that patients can be appropriately treated.