2,088 research outputs found
Biomass equations for tropical forest tree species in Mozambique
Chanfuta (Afzelia quanzensis Welw.), Jambire (Millettia stuhlmannii Taub.) and Umbila (Pterocarpus angolensis D.C.) are, among others, three of the main tropical tree species producing commercial timber in Mozambique. The present study employed destructive biomass estimation methods at three localities in Mozambique (Inhaminga, Mavume, and Tome) to acquire data on the mean diameter at breast height (DBH), and height of trees sampled in 21 stands each of Chanfuta and Jambire, and 15 stands of Umbila. Mean diameter at breast height (DBH) (ob) for Chanfuta, Jambire, and Umbila was: 33.8 ± 12.6 (range 13.5–61.1), 33.4 ± 7.4 (range 21.0–52.2), and 27.0 ± 9.5 (range 14.0–46.5) cm. The mean total values for biomass (kg) of trees of Chanfuta, Jambire, and Umbila trees were 864, 1016, and 321 respectively. The mean percentages of total tree biomass as stem, branch and leaf respectively were 54, 43, and 3 for Chanfuta; 77, 22, and 1 for Jambire; and 46, 51, and 3 for Umbila. The best fit species-specific equation for estimating total above ground biomass (AGB) was the power equation with only DBH considered as independent variable yielding coefficient of determination (R2) ranging from 0.89 to 0.97. At stand level, a total mean of 27.3 tons ha−1 biomass was determined of which studied species represented 94.6%. At plot level, total mean biomass for Jambire was 11.8 tons ha−1, Chanfuta and Umbila 9.9 and 4.1 tons ha−1 respectively. The developed power equation fitted total and stem biomass data well and could be used for biomass prediction of the studied species in Mozambique
A holistic understanding of scientific methodology
Philosophers of science are divided over the interpretations of scientific normativity. Larry Laudan defends a sort of goal-directed rules for scientific methodology. In contrast, Gerard Doppelt thinks methodological rules are a mixed batch of rules in that some are goal-oriented hypothetical rules and others are goal-independent categorical rules. David Resnik thinks that the debate between them is at a standstill now. He further thinks there are certain rules, such as the rule of consistency which is goal independent. However, he proposes a holistic understanding of the scientific methodology. Taking a thread from Resnik, the present paper also advocates a holistic understanding of the scientific methodology. Given that many scientific practices deal with systems, the focus will be given to the systems by assuming each as a constellation of methodological norms. By taking each system as a set of mutually supportive methodological rules whose instrumental values underwrite the coherence relation among them, the paper aims to provide what could be a viable holistic epistemological account that can explain scientific normativity at work in a scientific system. The paper will lay down specific holistic criteria for understanding the scientific methodology. They will be used to show how a holistic account could satisfactorily account for the success of the Compact Muon Solenoid (CMS) experiment in discovering the Higgs boson and how the holistic account can account for the instrumental error behind the apparent faster-than-light neutrino anomaly of the Oscillation Project with Emulsion-t Racking Apparatus (OPERA) experiments respectively
Observations of rotationally resolved C3 in translucent sight lines
The rotationally resolved spectrum of the A ^1Pi_u <- X ^1Sigma^+_g 000-000
transition of C3, centered at 4051.6A, has been observed along 10 translucent
lines of sight. To interpret these spectra, a new method for the determination
of column densities and analysis of excitation profiles involving the
simulation and fitting of observed spectra has been developed. The populations
of lower rotational levels (J<14) in C3 are best fit by thermal distributions
that are consistent with the kinetic temperatures determined from the
excitation profile of C2. Just as in the case of C2, higher rotational levels
(J>14) of C3 show increased nonthermal population distributions in clouds which
have been determined to have total gas densities below ~500 cm-3.Comment: 12 pages, 4 figures, accepted for publication in The Astrophysical
Journa
Determination of Deflection Function in A Rectangular Body
In this work, the authors consider a thick rectangular body, especially a plate, and try to investigate the flow of temperature and deflection function subjected to certain constraints according to their boundaries. Mathematically, the expression of temperature and deflection is found by utilizing standard integral transformation techniques
Ponseti method for treatment of idiopathic congenital talipes equinovarus at tertiary care center in India
Background: Different treatment methods were tried with variable success rates but Ponseti method of serial casting and manipulation stood apart due to better understanding of foot biomechanics and became accepted choice of treatment worldwide.Methods: 50 patients were enrolled in the study out of which 40 were available for final follow-up. We studied 40 cases during October 2018 to December 2020 at Government Medical College, Aurangabad. Out of 40 cases 31 were male and 9 were female. 25 were unilateral and 15 were bilateral. All cases were idiopathic. 4 inches Plaster of Paris (POP) bandages were cut into half and such 2 inches POP bandages were used for casting. Tenotomies were performed under controlled environment of Operation Theater with general anaesthesia. Number 12 surgical blade was used. Dennis-Browne splint was used for maintenance of correction.Results: Out of total 55 feet studied, 10 feet (18.18%) required tendo Achilles tenotomy and 45 feet (81.82%) were treated with casting alone. There were 8 cases of relapses (20%). All relapsed cases were treated with repeat casting as per Ponseti protocol and none of them required repeat tenotomy. Complications related to plaster were minimal and there were no incidence of rocker bottom deformity.Conclusions: We conclude that in a low income developing country like India where case load is very high; Ponseti method is effective, inexpensive form of treatment with minimal complications. Need for extensive soft tissue procedures vastly reduced with this method
Schistosoma haematobium co-infection with soil-transmitted helminthes: prevalence and risk factors from two communities in the central region of Ghana
Background: Schistosoma haematobium co-infection with S. mansoni and soil-transmitted helminthes afflict most-at-risk populations in endemic communities in the developing world. Aim: This study investigated S. haematobium co-infection with soil-transmitted helminthes, and host risk factors in two communities in the central region of Ghana. Methods: Schools and children were selected by stratified cluster and random sampling methods respectively. A total of 250 school children (aged 5 - > 20 years) were recruited. Teachers issued questionnaires to obtain information on host risk factors, water-contact activities and knowledge of S. haematobium infection. Urine and stool samples were examined for S. haematobium infection and S. mansoni and soil-transmitted helminthes using sedimentation quantitative and direct smear/formol-ether sedimentation concentration techniques respectively.Results: S. haematobium infection (1 - 50 eggs/10 ml urine) prevalence at Apewosika and Putubiw were 27.5 % and 17 % respectively. Males were more at risk of S. haematobium infection than females. S. haematobium co-infection with soil-transmitted helminthes (A. lumbricoides, E. histolytica, and T. trichuria) was recorded in Putubiw, with females more at risk than males. Children aged 16-19 and 10-15 were more at risk of S. haematobium infection and helminthic co-infection respectively. Haematuria and proteinuria were predictive of S. haematobium infection. School children had poor knowledge of S. haematobium infection. Water-contact activity was common.Conclusion: S. haematobium prevalence and its co-infection with soil-transmitted helminthes were common in Putubiw. Watercontact activity and poor knowledge about S. haematobium infection were major risk factors. Increased education on preventive and control measures especially in schools is recommended.Key words: Haematuria, proteinuria, Schistosoma haematobium, S. mansoni, helminthes, Bulinus globosu
Explaining SAT Solving Using Causal Reasoning
The past three decades have witnessed notable success in designing efficient SAT solvers, with modern solvers capable of solving industrial benchmarks containing millions of variables in just a few seconds. The success of modern SAT solvers owes to the widely-used CDCL algorithm, which lacks comprehensive theoretical investigation. Furthermore, it has been observed that CDCL solvers still struggle to deal with specific classes of benchmarks comprising only hundreds of variables, which contrasts with their widespread use in real-world applications. Consequently, there is an urgent need to uncover the inner workings of these seemingly weak yet powerful black boxes.
In this paper, we present a first step towards this goal by introducing an approach called {CausalSAT}, which employs causal reasoning to gain insights into the functioning of modern SAT solvers. {CausalSAT} initially generates observational data from the execution of SAT solvers and learns a structured graph representing the causal relationships between the components of a SAT solver. Subsequently, given a query such as whether a clause with low literals blocks distance (LBD) has a higher clause utility, {CausalSAT} calculates the causal effect of LBD on clause utility and provides an answer to the question. We use {CausalSAT} to quantitatively verify hypotheses previously regarded as "rules of thumb" or empirical findings, such as the query above or the notion that clauses with high LBD experience a rapid drop in utility over time. Moreover, {CausalSAT} can address previously unexplored questions, like which branching heuristic leads to greater clause utility in order to study the relationship between branching and clause management. Experimental evaluations using practical benchmarks demonstrate that {CausalSAT} effectively fits the data, verifies four "rules of thumb", and provides answers to three questions closely related to implementing modern solvers
Wetting of Curved Surfaces
As a first step towards a microscopic understanding of the effective
interaction between colloidal particles suspended in a solvent we study the
wetting behavior of one-component fluids at spheres and fibers. We describe
these phenomena within density functional theory which keeps track of the
microscopic interaction potentials governing these systems. In particular we
properly take into account the power-law decay of both the fluid-fluid
interaction potentials and the substrate potentials. The thicknesses of the
wetting films as a function of temperature and chemical potential as well as
the wetting phase diagrams are determined by minimizing an effective interface
potential which we obtain by applying a sharp-kink approximation to the density
functional. We compare our results with previous approaches to this problem.Comment: 54 pages, 17 figures, accepted for publication in Physica
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