Process Of Retraction Research Articles

Intrusion and retraction with an innovative crane spring

Today, one of the most common lines of treatment for gummy smiles is the use of temporary anchorage devices (TADs). One of the major issues with the TADs is the unpredictability of stability during treatment. Additional to the loosening of TAD, gingival tissue overgrowth, especially when placed above the attached gingiva, is a persistent issue. During the process of intrusion and retraction, the point of force attachment in relation to the center of resistance is of prime importance to achieve the correct and required vector of force. This, at most times, is not achievable with TADs due to the interference of the roots of teeth. Thus, an alternative to TADs with the convenience of placing the point of force attachment anywhere in the buccal vestibule is discussed here in. This article describes the design and action of an innovative spring (Crane spring) wherein the point of force attachment can be varied to suit the biomechanics apart from delivering light and continuous forces using looped mechanics. The spring is of a simple design and can be easily constructed. It is highly efficient with intrusion and retraction.

Nanoscopic wetting behaviour of single oil droplets on a fibre

Multiphase fluids that contain dispersed oil droplets are fundamental to many industrial processes and formulated products. In the present work, the surface wetting and interaction between an emulsion droplet and a single fibre were quantitatively investigated as a function of surfactant chemistry, pH, and salt concentration using an optical tweezers apparatus. Silicone droplets were emulsified in water and stabilised by surfactants. An individual droplet was captured using an optical tweezers setup to allow a controlled contact with a fibre surface. During the approach process, the surface interaction was measured and spreading behaviour was quantified after contact was made between the droplet and fibre. Salt concentration was increased to change the surface interaction behaviour. The pH and ζ-potential of silicone emulsions decreased from 9.5 to 6.0 and from 39 mV to − 15 mV, respectively, when increasing salt concentration for both of the surfactants studied, SDS and CTAB. The attraction between the fibre and a silicone oil droplet was found to increase as the electrostatic repulsion was suppressed with an increased salt concentration. This was confirmed by an increased number of droplet-fibre adhesion events and in some cases droplet spreading on the fibre. Such observations for adhesion are based on electrostatic attractions exceeding the maximum force that can be exerted by the trapping laser. When adhesion was not observed, attraction could still be recorded through a thin-film hydrodynamic suction effect during the process of retraction, which becomes more pronounced on the polyester fibre. Our results provide a novel method to directly quantify the surface interaction and wetting of liquid droplets on microscopic fibres simultaneously, which could be valuable when investigating formulated products that involve emulsion droplets.

Morphological features of heart damages caused by national Uzbek knives

Damage to the body caused by the action of sharp objects is one of the topical topics of forensic criminology. The variety of existing objects that can potentially be used for the purpose of committing a crime require a detailed traceological study. Purpose of the work: to carry out an analysis according to the study of the features of the morphology of heart stab-cut wounds, inflicted by national Uzbek knives. The material presented by 30 observations of those who died as a result of inflicting penetrating stab wounds with damage to the heart, inflicted by national Uzbek knives. Statistical processing of the obtained results was carried out using the MS Excel 2007 software. It was found that stab-cut wounds were more common in men, the wounds were mainly in the ventricles and less often in the atria. Stab-cut wounds inflicted by Uzbek national knives have an angular, oval, linear shape. The butt ends are П-, Г-, T-shaped, the blade ends are sharp. It was revealed that the walls of the heart, in comparison with skin wounds, have a higher morphological identification significance. The heart after restoration in Ratnevsky’s solution deformed less than skin wounds, and the length of the stab-cut wounds of the heart more accurately corresponds to the width of the blade of a stab-cut weapon. This may be due to the peculiarities of the structure of the epicardium and myocardium, which are less susceptible to the process of retraction. On the tissues of the heart, the design features of the butt and blade of knife blades are quite fully determined, so they can be used for group identification of a traumatic weapon.

Non-prophylactic resveratrol-mediated protection of neurite integrity under chronic hypoxia is associated with reduction of Cav1.2 channel expression and calcium overloading.

Cellular hypoxia is a major cause of oxidative stress, culminating in neuronal damage in neurodegenerative diseases. Numerous ex vivo studies have implicated that hypoxia episodes leading to disruption of Ca2+ homeostasis and redox status contribute to the progression of various neuropathologies and cell death. Isolation and maintenance of primary cell culture being cost-intensive, the details of the time course relationship between Ca2+ overload, L-type Ca2+ channel function, and neurite retraction under chronic and long-term hypoxia remain undefined. In order to explore the effect of oxidative stress and Ca2+ overload on neurite length, first, we developed a 5-day-long neurite outgrowth model using N2a cell line. Second, we propose a chronic hypoxia model to investigate the modulation of the L-type Ca2+ channel (Cav1.2) and oxidative resistance gene (OXR1) expression level during the process of neurite retraction and neuronal damage over 32h. Thirdly, we developed a framework for quantitative analysis of cytosolic Ca2+, superoxide formation, neurite length, and constriction formation in individual cells using live imaging that provides an understanding of molecular targets. Our findings suggest that an increase in cytosolic Ca2+ is a feature of an early phase of hypoxic stress. Further, we demonstrate that augmentation in the L-type channel leads to amplification in Ca2+ overload, ROS accumulation, and a reduction in neurite length during the late phase of hypoxic stress. Next, we demonstrated that non-prophylactic treatment of resveratrol leads to the reduction of calcium overloading under chronic hypoxia via lowering of L-type channel expression. Finally, we demonstrate that resveratrol-mediated reduction of Cav1.2 channel and STAT3 expression are associated with retention of neurite integrity. The proposed in vitro model assumes significance in the context of drug designing and testing that demands monitoring of neurite length and constriction formations by imaging before animal testing.

Changes in Active and Non-Excitable Adjacent Nerve Membranes after Electroactivation

It has long been recognized that parabiosis and paranecrosis are two close cytological theories that have demonstrated the intermediate state of the cell between life and death from various scientific positions. However, they have not previously been shown by anyone at the same time on the same object. This became the goal of our electron microscopic work. Active and non-excitable membranes of nerve and glial cells under pessimal inhibition have been studied. The main sign of paranecrosis was considered denaturation and aggregation of membrane protein, manifested in a decrease in its degree of dispersion and dehydration. Parabiosis was caused by the pessimal frequency of electroactivation of the sympathetic ganglion of white rats. As a result, the axolemma turned into a thick membrane, reinforced with fringe and the appearance of desmosomes. There were protein sticking from the inside of the neurolemma in the form of pyramids, which, by retracting, curved the membrane. In its bends, pyramid-like loose aggregates of intermembrane protein were formed from the outer sides of the glial and axolemm membranes, which, merging, turned into a kind of hourglass and septa. The septa were localized in the intercellular slits of axons and glia and often crossed both membranes. In chemical synapses, the shell of dendrites turned out to be denser than that of presynaptic axons. The process of protein aggregation and retraction locally narrows the intercellular axo-axonal and axo-glial cleft. Gap and tight junctions (GJ and TJ) are formed. So, for the first time we got a way of their experimental education. All reactive changes that occur de novo are considered as one reversible process of denaturation and aggregation of the mass of intrinsic and near-membrane proteins developed under the influence of frequency electrical stimulation. The pulse of the drug is restored within minutes. It is assumed that the revealed changes, paranecrosis, are a morphological manifestation of parabiosis.

O-095 Is the process to retract fabricated randomised clinical trials in reproductive medicine working sufficiently?

Abstract Study question How do journal editors and publishers respond on randomised clinical trials in reproductive medicine that have been identified as fabricated? Summary answer Despite clear proof of fabrication, only a small minority of fabricated RCTs is retracted within 12 months. What is known already Randomised controlled trials (RCTs) are recognised as scientific investigations that have the least potential for bias and are therefore widely used to direct clinical practice. The validity of data in RCTs matters to the accountability of medical practice and the wellbeing of patients. Detection of integrity problems and subsequent action is therefore of imminent importance. Across all fields of medicine, it takes on average 4 years for papers labelled with research misconduct to be retracted. While this is partially explained by the time needed to detect the misconduct, the process of investigation and retraction is also slow and bureaucratic. Study design, size, duration We studied the articles of 4 authors who have published 52 clearly fabricated RCTs in obstetrics/gynaecology. Data fabrication was clear from duplicate baseline and outcome tables in studies on different interventions done in different patients in different periods. The duplications could be from the author themselves, or from other articles. Our findings were published in the public domain for 3 of the 4 authors, with an article on the fourth author being submitted. Participants/materials, setting, methods After detection of the fabrication, we approached authors and their institutes for an explanation. As a satisfying explanation was not given, we notified the editors of the involved 14 journals in February 2020. The universities where two of the authors were awarded a PhD were informed in August 2020. Here we compare the journals’ response to Committee on Publication Ethics (COPE)-guidelines, we report the percentage of retracted papers and other responses of editors and publishers. Main results and the role of chance Two articles had already been retracted prior to our notification. Twelve months after we had notified the editors, 4/50 (8%) (1 journal) of the articles had been retracted, 3 (6%) (2 journals) were formally investigating with notification on their website, 6/50 (8%) (3 journals) were informally investigating (without visible notification), 3/50 (6%) (1 journal) had made an expression concern and stated “caution that clinical practice or guidelines should not be based on this report” without formal retraction, and one (2%) had investigated original data and cleared it (although numerous data were identical to a study published 10 years earlier). For the other 33 articles (11 journals) no visible action had been taken. None of the journals provided feedback to the whistle-blower as required by COPE. The University of Utrecht and the Vrije Universiteit Brussel had not taken any action against the awarded fraudulent PhDs. Among the reactions of editors were the statements “I have been in the business long enough; It exists in all specialties and in every country”, “we receive 80 submissions a week, I am too busy to respond on this” and “we did still not get an answer about the result of the investigation by the local court”. Limitations, reasons for caution This was a sample of four authors who had published 52 articles. There might be investigations ongoing that are not visible for the outside world. Wider implications of the findings Retraction of fabricated studies is seldom happening, and a majority of journals is not following COPE. This not only puts patients at risk, but it also lets whistle-blowers down and it jeopardises the trustworthiness of research. COPE-regulations consider the interests of authors and publishers, but not the interests of patients. Trial registration number Not applicable

Aspects of change in New York City English short-a

AbstractThis article focuses on change in the “short-a system” of New York City English (NYCE). Recent results suggest that a complex set of tensing rules traditionally described for NYCE are being replaced by several simpler systems. This article reports on a study of this change using a recently developed large audio-aligned parsed speech corpus (CoNYCE). This change is similar to the simplification reported for Philadelphia by Labov et al. (2016). Unlike in the Philadelphia case, however, our results do not show evidence of a single abstract process of change. Our findings, rather, suggest at least two separate changes in the community—one affecting short-a in prenasal contexts and a second affecting pre-oral obstruent contexts. In addition, the results suggest an additional independent process of lowering and retraction affecting short-a sounds in contexts not targeted by the process of phonological reorganization, that is, “trap-backing.”

Theoretical Implications of Directionally Asymmetric Transparency

Transparent segments have been a well known challenge for accounts of patterns of long distance agreement, such as vowel and consonant harmony. Two standard ways to account for transparency are autosegmental feature spreading with underspecification (e.g. Kiparsky 1981; Steriade 1987) and Agreement by Correspondence (ABC; Walker 2000; Walker & Rose 2004; Hansson 2001). Both, however, fail to derive the multiple instances of transparency encountered in Tsilhqút'í­n (Cook 1993; 2013). Here, non-retracted dorsals act both as transparent and as opaque to the process of vowel retraction, depending on which side of the trigger, a retracted sibilant, they are located. On the other hand, both retracted and non-retracted dorsals are transparent in sibilant harmony, in which sibilants are forced to agree in retraction. I propose a superset approach that combines feature spreading and underspecification with ABC: All dorsals are transparent in sibilant harmony, because they are outside the correspondence relation. At the first step of the derivation, non-retracted dorsals are not specified for retraction, allowing them to be transparent to regressive retraction. At a later step, they are negatively specified and hence able to block progressive retraction.

On the Phonology and Semantics of Deaccentuation

The deaccentuation of given and/or repeated elements is familiar from many dialects of English. We propose that deaccentuation is essentially an optional postlexical phonological process of stress retraction triggered by two constraints: *Stress-Copy, which assigns a violation to a stress peak on a word with a segmentally identical copy in the left context, and Rightmost, which assigns a violation to every word between a stress peak and the right phrase edge. We quantify deaccentuation by defining it as being perceived with less stress than expected, where expected stress is calculated by an implementation of Liberman and Prince's (1977) phrasal stress algorithm. We provide empirical evidence for our analysis based on the first inaugurals of six former U.S. presidents.

Droplet impacting a superhydrophobic mesh array: Effect of liquid properties

For numerous applications in microfluidic engineering, material science, and drug production, droplets of desired size and distribution are generated through liquid impingement on a perforated substrate. The dynamic process of droplet impact, spread, retraction, penetration, jet formation, and fragmentation into satellite droplets is simulated in a droplet impacting a mesh array configuration using an advanced lattice-Boltzmann method. The Weber number and Ohnesorge number are found to significantly influence the dynamics and outcomes, which can be explained by a qualitative and quantitative analysis based on the force and energy balance.

Expressive Sibilant Retraction in North Norwegian: morpheme or ‘spoken gesture’?

North Norwegian has a contrast between /s/ and /ʂ/ that is neutralized in word-initial position before a consonant, and an optional process of Expressive Sibilant Retraction (ESR), which changes /s/ to [ʂ] in precisely the environment where the contrast is neutralized (Broch 1927). ESR appears ambiguous between a word formation process and a spoken gesture (Okrent 2002; Perlman et al. 2015). On the one hand, ESR exploits givens of phonological structure. On the other, treating it as a morphological process entails claiming that the spell-out of certain (“expressive”) morphemes may take place after phonological processes have applied, or that the realization of these morphemes takes precedence to phonological constraints. I argue that ESR is a communicative (i.e. non-linguistic, or post-linguistic) spoken gesture that nonetheless exploits the suspension of phonological generalizations in a way that directs attention to its iconic function. I describe the varied interpretations that ESR has depending on whether it indexes an action/event, object, or state/property, and propose that these share a common semantic core. This gesture-based account of ESR is offered as a possible model for “expressive phonology” (e.g. Diffloth 1979) in other languages.

Platelet bioenergetics and its implications in disease

Bioenergetics drives energy production for mechanical processes that are critical to platelet functions, e.g., adhesion, spreading, aggregation, clot formation and contraction. Storage and pathological conditions e.g., stroke, sepsis, diabetes etc., alters platelet energetics and function; however, the specific mechanisms governing these alterations are not clear. It is not well understood which metabolic fuels can be used and which are required. We are investigating the roles of different metabolic pathways in the energy consuming process of clot retraction. Using a spectrum of techniques from in vitro platelet functional assays to biochemical methods, whole animal models, and measurement of bioenergetic functions of mitochondria we are elucidating platelet bioenergetics and its implications in disease. We developed a simple method for measuring clot contraction kinetics using time lapse imaging. Our system is efficient, high throughput and is favorable to study platelet bioenergetics of clot formation and retraction. We hypothesize that, upon activation with thrombin, fuel use can be highly plastic, depending on the fuels available. We found that glycolysis and oxidative phosphorylation can both contribute to provide energy for platelet function. Inhibitors of glycolysis and oxidative phosphorylation using 2‐Deoxyglucose and oligomycin inhibited clot retraction showing that both these processes are important.We have also begun to examine bioenergetics in platelets from diabetics. Platelets from type2 diabetes patients have been shown to have abnormal mitochondrial membrane potential, membrane fluidity, ATP content, and oxidative stress. However, the impact of diabetes on platelet bioenergetics is less clear. We have developed a mouse model to probe the role of mitochondria and oxidative phosphorylation in platelet function. TFAM (Mitochondrial Transcription factor A) regulates mitochondria DNA copy number and transcription of mitochondrial DNA encoded proteins. The regulation of mitochondrial DNA is necessary for mitochondrial biogenesis. We have selectively deleted TFAM in the megakaryocyte lineage using the Platelet factor 4 promoter driven Cre‐Lox system. This model will be very useful, and it supports our in vitro studies with metabolic inhibitors in understanding the role of mitochondria and oxidative phosphorylation in platelet function in platelet bioenergetics contributing to the thrombosisSupport or Funding InformationSupported by HL56652, HL138179 and VA Merit AwardThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Development of human brain neurons

Neurodevelopment The earliest stages of human brain development are very difficult to monitor, but using induced pluripotent stem cells (iPSCs) can help to elucidate the process. Real et al. transplanted neural progenitors derived from human iPSCs into the brains of adult mice. They used intravital imaging to visualize how resulting neurons grew and connected. The human cells produced neurons that integrated and developed synaptic networks with oscillatory activity. Dendritic pruning was observed and involved a process of branch retraction, not degeneration. Cells derived from individuals with Down syndrome, upon transplantation into the mouse brain, produced neurons that grew normally but showed reduced dendritic spine turnover and less network activity. Science , this issue p. [eaau1810][1] [1]: /lookup/doi/10.1126/science.aau1810

In vivo modeling of human neuron dynamics and Down syndrome.

Harnessing the potential of human stem cells for modeling the physiology and diseases of cortical circuitry requires monitoring cellular dynamics in vivo. We show that human induced pluripotent stem cell (iPSC)-derived cortical neurons transplanted into the adult mouse cortex consistently organized into large (up to ~100 mm3) vascularized neuron-glia territories with complex cytoarchitecture. Longitudinal imaging of >4000 grafted developing human neurons revealed that neuronal arbors refined via branch-specific retraction; human synaptic networks substantially restructured over 4 months, with balanced rates of synapse formation and elimination; and oscillatory population activity mirrored the patterns of fetal neural networks. Lastly, we found increased synaptic stability and reduced oscillations in transplants from two individuals with Down syndrome, demonstrating the potential of in vivo imaging in human tissue grafts for patient-specific modeling of cortical development, physiology, and pathogenesis.

Set-theoretic solutions of the Yang–Baxter equation, braces and symmetric groups

We involve simultaneously the theory of braided groups and the theory of braces to study set-theoretic solutions of the Yang–Baxter equation (YBE). We show the intimate relation between the notions of “a symmetric group”, in the sense of Takeuchi, i.e. “a braided involutive group”, and “a left brace”. We find new results on symmetric groups of finite multipermutation level and the corresponding braces. We introduce a new invariant of a symmetric group (G,r), the derived chain of ideals ofG, which gives a precise information about the recursive process of retraction of G. We prove that every symmetric group (G,r) of finite multipermutation level m is a solvable group of solvable length ≤m. To each set-theoretic solution (X,r) of YBE we associate two invariant sequences of involutive braided groups: (i) the sequence of its derived symmetric groups; (ii) the sequence of its derived permutation groups; and explore these for explicit descriptions of the recursive process of retraction of (X,r). We find new criteria necessary and sufficient to claim that (X,r) is a multipermutation solution.

Interactions between micro-scale oil droplets in aqueous surfactant solution determined using optical tweezers

HypothesisThe stability of the emulsions is crucial, which relies on a well-developed understanding of dynamic interaction forces between single dispersed droplets. In the previous studies, many interests focus on the oil droplets of size range of 20–200 µm. However, emulsion droplets with diameter below 10 µm are rarely mentioned, which is the size scale of real emulsion droplets in various applications, such as toners, spacers for liquid crystal displays, and materials in biomedical and biochemical analysis. The micro-scale droplets have many differences on the deformation, internal pressure and hydrodynamic effects. It is necessary to understand the interaction mechanisms between two real size scales of oil droplets for guiding practical production and application. ExperimentsIn this work, tetradecane was chosen as the model oil phase in all experiments. The interaction forces of two tetradecane droplets with the diameter of 5.0 µm in water in the presence of surfactant and salt solution were directly measured using optical tweezers. The force-distance curves were established, and the zeta potential of tetradecane droplets was studied using Zetasizer Nano ZSP. FindingsThe absolute value of zeta potential of tetradecane droplets was found to decrease with the increase of salt concentration and increase with the increase of surfactant concentration. The repulsive force between two tetradecane droplets was found to decrease with the increase of salt concentration because the electrostatic double-layer force was suppressed gradually with the increase of salt concentration. The “hydrodynamic suction” effect during the process of retraction becomes more pronounced due to the corresponding increase in the hydrodynamic force with the increase of the approaching velocity between the tetradecane droplets. Furthermore, we found the existing model for the measurement of large droplets by atomic force microscope (AFM) is invalid for the measurement of micro-scale droplets by optical tweezers. The deformation of colliding micro-scale droplets can be safely ignored, which is quite different from the large droplets. Our results provide a useful method to study the interaction forces between micro-scale emulsion droplets with pN force resolution, and gives a deep insight of the stabilization mechanism of real size scale of O/W emulsions. These findings have significant implications on the stability of emulsions in many food, cosmetics, medicine, and advanced materials.

Platelet packing density is an independent regulator of the hemostatic response to injury

Background Hemostasis studies performed in vivo have shown that hemostatic plugs formed after penetrating injuries are characterized by a core of highly activated, densely packed platelets near the injury site, covered by a shell of less activated and loosely packed platelets. Thrombin production occurs near the injury site, further activating platelets and starting the process of platelet mass retraction. Tightening of interplatelet gaps may then prevent the escape and exchange of solutes. Objectives To reconstruct the hemostatic plug macro- and micro-architecture and examine how platelet mass contraction regulates solute transport and solute concentration in the gaps between platelets. Methods Our approach consisted of three parts. First, platelet aggregates formed in vitro under flow were analyzed using scanning electron microscopy to extract data on porosity and gap size distribution. Second, a three-dimensional (3-D) model was constructed with features matching the platelet aggregates formed in vitro. Finally, the 3-D model was integrated with volume and morphology measurements of hemostatic plugs formed in vivo to determine how solutes move within the platelet plug microenvironment. Results The results show that the hemostatic mass is characterized by extremely narrow gaps, porosity values even smaller than previously estimated and stagnant plasma velocity. Importantly, the concentration of a chemical species released within the platelet mass increases as the gaps between platelets shrink. Conclusions Platelet mass retraction provides a physical mechanism to establish steep chemical concentration gradients that determine the extent of platelet activation and account for the core-and-shell architecture observed in vivo.

The fate of endemic insects of the Andean region under the effect of global warming.

Three independent but complementary lines of research have provided evidence for the recognition of refugia: paleontology, phylogeography and species distributional modelling (SDM). SDM assesses the ecological requirements of a species based on its known occurrences and enables its distribution to be projected on past climatological reconstructions. One advantage over the other two approaches is that it provides an explicit link to environment and geography, thereby enabling the analysis of a large number of taxa in the search for more general refugia patterns. We propose a methodology for using SDM to recognize biogeographical patterns of endemic insects from Southern South America. We built species distributional models for 59 insect species using Maxent. The species analyzed in the study have narrow niche breadth and were classified into four assemblages according to the ecoregion they inhabit. Models were built for the Late Pleistocene, Mid-Holocene and Present. Through the procedure developed for this study we used the models to recognize: Late Pleistocene refugia; areas with high species richness during all three periods; climatically constant areas (in situ refugia); consistent patterns among in situ refugia, Pleistocene refugia and current distribution of endemic species. We recognized two adjacent Pleistocene refugia with distinct climates; four in situ refugia, some of which are undergoing a process of fragmentation and retraction or enlargement. Interestingly, we found a congruent pattern among in situ refugia, Pleistocene refugia and endemic species. Our results seem to be consistent with the idea that long-term climate stability is known to have a key role in promoting persistence of biodiversity in an area. Our Pleistocene and in situ refugia are consistent with refugia identified in studies focusing on different taxa and applying other methodologies, showing that the method developed can be used to identify such areas and prove their importance for conservation.

Socioeconomic and demographic characterization of an endemic malaria region in Brazil by multiple correspondence analysis

BackgroundIn the process of geographical retraction of malaria, some important endemicity pockets remain. Here, we report results from a study developed to obtain detailed community data from an important malaria hotspot in Latin America (Alto Juruá, Acre, Brazil), to investigate the association of malaria with socioeconomic, demographic and living conditions.MethodsA household survey was conducted in 40 localities (n = 520) of Mâncio Lima and Rodrigues Alves municipalities, Acre state. Information on previous malaria, schooling, age, gender, income, occupation, household structure, habits and behaviors related to malaria exposure was collected. Multiple correspondence analysis (MCA) was applied to characterize similarities between households and identify gradients. The association of these gradients with malaria was assessed using regression.ResultsThe first three dimensions of MCA accounted for almost 50% of the variability between households. The first dimension defined an urban/rurality gradient, where urbanization was associated with the presence of roads, basic services as garbage collection, water treatment, power grid energy, and less contact with the forest. There is a significant association between this axis and the probability of malaria at the household level, OR = 1.92 (1.23–3.02). The second dimension described a gradient from rural settlements in agricultural areas to those in forested areas. Access via dirt road or river, access to electricity power-grid services and aquaculture were important variables. Malaria was at lower risk at the forested area, OR = 0.55 (1.23–1.12). The third axis detected intraurban differences and did not correlate with malaria.ConclusionsLiving conditions in the study area are strongly geographically structured. Although malaria is found throughout all the landscapes, household traits can explain part of the variation found in the odds of having malaria. It is expected these results stimulate further discussions on modelling approaches targeting a more systemic and multi-level view of malaria dynamics.

Comparative evaluation of stress related changes in the periodontium during conventional and rapid canine retraction – a finite element study

Assessment of stress related changes in the periodontium is of prime importance while applying forces of differential magnitude. A detailed knowledge of these stresses in the biological systems provides an insight on the favorable and unfavorable responses during a clinical procedure over time. Material and Methods: Two patients undergoing fixed orthodontic treatment requiring extraction of their first premolars were selected for the study, canine retraction with 150 grams force using Niti coil spring in one subjects and other subject for canine retraction with 250 grams of force by dentoalveolar distraction with a distraction device was performed. Results: A nonparametric, Mann-Whitney U test was performed for the comparison of two procedures and it was observed that the stresses generated in the teeth, periodontal ligament and bone were considerably high in rapid canine retraction method compared to the conventional method of canine retraction. Conclusion: Rapid canine retraction generates considerable amount of excessive stresses in the periodontium. Displacements per activation were within the physiological limits, which in turn induces bone remodelling resulting in tooth movement with minimal or no anchor loss. Rapid canine retraction is a physiologically acceptable process of canine retraction with clinically minimal or no side effects on the periodontium. Keywords: Conventional, Rapid, Stress distribution, Finite element analysis