bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Two Different Bracket Base Cleaning Procedures on Shear Bond Strength Reliability
Authors: Aksu Muge , Kocadereli Ilken
Published: June 2013

Purpose

To search if the shear bond strengths of brackets would change after two different base-cleaning procedures such as sandblasting or carbide bur cleaning, and to determine if a previously bonded tooth surface had any effect on bond strength.

Materials and methods

A total of 120 new brackets were first bonded to 120 extracted premolars and then debonded and bond strength was recorded. The debonded brackets were divided into two groups and recycled either by sandblasting or tungsten-carbide bur cleaning. Sixty recycled brackets were divided into two subgroups: In each group; 30 recycled brackets were bonded to unused 30 extracted premolars. The remaining brackets were bonded to 30 previously used premolars. The brackets were debonded again and their bond strengths were remeasured.

Results

Bond strength of rebonded brackets after sandblasting was not significantly different from that of new brackets while the bond strength of rebonded brackets after carbide bur cleaning group significantly decreased. The previously bonded tooth surface did not affect the bond strength significantly.

Clinical significance

This study showed that rebonding the brackets after sandblasting supplies sufficient bond strength. Previously bonded tooth surface did not cause a decreasing effect on bond strength. However, when carbide bur cleaning procedure is chosen, the clinician should proceed cautiously.

How to cite this article

Aksu M, Kocadereli I. Influence of Two Different Bracket Base Cleaning Procedures on Shear Bond Strength Reliability. J Contemp Dent Pract 2013;14(2):250-254.
Influence of Acrylic Resin Polymerization Methods on Residual Monomer Release
Authors: Tuna Elif Bahar , Rohlig Bilge Gokcen , Sancakli Erkan , Evlioglu Gulumser , Gencay Koray
Published: June 2013

Aim

The aim of this study was to quantify and compare the amount of methyl methacrylate (MMA) monomer released from three different denture base acrylic material processed by different polymerization methods and storage conditions.

Materials and methods

Microwave-cured, conventional heat and injection-technique acrylic polymerized materials were stored in neutral (pH = 7) and acidic (pH = 4.5) artificial saliva for 24 hours at the room temperature, separately. The residual MMA content was determined by high performance liquid chromatography (HPLC).

Results

The MMA leaching from resins showed that microwave-cured material has lower residual MMA leach compared both conventional and injection-technique on neutral saliva storage conditions.

Conclusion

The all data's exhibited higher MMA release into an acidic saliva environment than neutral artificial saliva and there were no significant differences between the materials groups on acidic saliva storage conditions.

Clinical significance

Microwave polymerization method might has some advantages on reducing release of MMA concentration and may contributory effect upon polymerization reaction on neutral pH storage condition, therefore methods of polymerization should be considered as amount of monomer release.

How to cite this article

Tuna EB, Rohlig BG, Sancakli E, Evlioglu G, Gencay K. Influence of Acrylic Resin Polymerization Methods on Residual Monomer Release. J Contemp Dent Pract 2013;14(2):259-264.
A New Solvent-free One-Step Self-Etch Adhesive: Bond Strength to Tooth Structures
Authors: Khoroushi Maryam , Shirban Farinaz , Shirban Mohammadreza
Published: June 2013

Introduction

In recent years some new solvent-free dental adhesives have been marketed. This study evaluated bonding effectiveness of a new one-step solvent-free self-etch adhesive in comparison with a common two-step self-etch adhesive used as gold standard.

Materials and methods

Flat enamel and dentin surfaces were prepared on 60 incisors using silicon carbide papers. Clearfil SE Bond (CSEB) and Bond 1SF (B1SF) adhesives were applied on enamel/dentin surfaces in four groups (n = 15): (1) Enamel surface and CSEB, (2) dentin surface and CSEB, (3) enamel surface and B1SF, (4) dentin surface and B1SF. Composite resin buildups were carried out using Z100 composite resin. All the specimens were stored for 24 hours at 37¢XC and 100% relative humidity. After 500 rounds of thermocycling, shear bond strength (SBS) test was performed using a universal testing machine at 1 mm/min crosshead speed. Data were analyzed with one-way ANOVA and a post hoc Tukey test (α = 0.05). In each experimental group, two additional specimens were prepared for scanning electron microscopy evaluation.

Results

Significant differences were observed between the study groups (p < 0.001). The highest enamel/dentin bond strengths were recorded in group 1 (CSEB) (p < 0.001). The SBS of the two-step self-etch adhesive to enamel and dentin was significantly higher than that of the one-step self-etch adhesive (p < 0.001). There was no significant difference between enamel and dentin SBS with B1SF (p = 0.559).

Conclusion

Within the limitations of the present study, when bonded to enamel and dentin the solvent-free adhesive B1SF underperforms as compared to CSEB as the control gold standard.

How to cite this article

Shirban F, Khoroushi M, Shirban M. A New Solvent-free One-Step Self-Etch Adhesive: Bond Strength to Tooth Structures. J Contemp Dent Pract 2013;14(2):269-274.
A Survey of Endodontic Practices among Dentists in Nigeria
Authors: Jafarzadeh Hamid , Udoye Christopher I , Sede Matthew A , Abbott Paul V
Published: June 2013

Aim

To investigate the pattern of routine endodontic practices among Nigerian dentists.

Materials and methods

This study was a questionnaire-based survey of samples of dentists in the Nigerian cities of Enugu and Benin. The self-administered questionnaire contained 25 close-ended questions with multiple choice options. The data collected included demographic details of respondents, root canal preparation techniques, irrigants and intracanal medicaments used, the number of appointments, method of working length determination, root filling techniques, cements used, and the scope of treatment performed.

Results

Most respondents used sodium hypochlorite as the irrigant, the step back technique for canal preparation, and lateral condensation with a zinc oxide-eugenol-based sealer for obturation. Most respondents did root canal treatment on all types of teeth and used radiographs to determine the working length 70% of the time. Most respondents followed up their patients for less than 12 months and most treated teeth with periapical areas larger than 10 mm by root canal therapy combined with apical surgery.

Conclusion

Most Nigerian dentists use step back technique for canal preparation and lateral condensation for obturation.

Clinical significance

Endodontic practice by Nigerian dentists differs from some established practice quality guidelines in many other countries, particularly in nonperfusion of modern techniques into practice, popularity of antibiotic use for endodontic emergencies and a high rate of perforations.

How to cite this article

Udoye CI, Sede MA, Jafarzadeh H, Abbott PV. A Survey of Endodontic Practices among Dentists in Nigeria. J Contemp Dent Pract 2013;14(2):293-298.
Ergonomics and Musculoskeletal Disorder: As an Occupational Hazard in Dentistry
Authors: Gopinadh Anne , Devi Kolli Naga Neelima , Chiramana Sandeep , Manne Prakash , Sampath Anche , Babu Muvva Suresh
Published: June 2013

Objective

Musculoskeletal disorders (MSDs) are commonly experienced in dentistry. The objective of this study is to determine the prevalence of ergonomics and MSDs among dental professionals.

Materials and methods

A cross-sectional survey was conducted among 170 dentists of different specialties. The questionnaire gathered information regarding demographic details, MSDs, work duration, working status, awareness of ergonomics, etc. Data was analyzed using SPSS version 15.0. Student's t-test and analysis of variance (ANOVA) test was used for comparison in mean scores. Stepwise multiple linear regression analysis was used to assess the independent variables that significantly influenced the variance in the dependent variable (pain).

Results

It was found that 73.9% of the participants reported musculoskeletal pain and most common painful sites were neck and back. More than half of the participants, i.e. 232 (59.3%) were aware of correct ergonomic posture regarding dental. Almost percentage of pain increased significantly with increase in age and working time. Among all specialties, prosthodontics were found to have more prevalence of MSDs.

Clinical significance

The appearance of musculoskeletal symptoms among dental professionals was quite common. It suggested that ergonomics should be covered in the educational system to reduce risks to dental practitioners.

How to cite this article

Gopinadh A, Devi KNN, Chiramana S, Manne P, Sampath A, Babu MS. Ergonomics and Musculoskeletal Disorder: As an Occupational Hazard in Dentistry. J Contemp Dent Pract 2013;14(2):299-303.
Heritability of Thirty Cephalometric Parameters on Monozygotic and Dizygotic Twins: Twin Study Method
Authors: Reddy T Praveen Kumar , Kumar B Sunil , Sreedevi Gojja , Srinivas Baratam , Prasad CMS Krishna , Satish R
Published: June 2013

Genetic mechanisms are already predominant during embryonic craniofacial morphogenesis, but environment is also thought to influence dentofacial morphology postnatally, particularly during facial growth. A better understanding of the relative effects of genes and environment on dentofacial and occlusal parameters should improve our knowledge on the etiology of orthodontic disorders and therefore also on the possibilities and limitations of the orthodontic treatment and treatment planning. The aim of the present study is to explore the genetic and environmental influence on craniofacial dimensions in a group of 19 pairs of twins using the twin study method. The twin study carried out here clearly indicates that craniofacial matrix is under substantial genetic control and the redirection of a basic growth pattern may be modified only within biological limits which are harmonious for the patient.

How to cite this article

Sreedevi G, Srinivas B, Reddy TPK, Prasad CMSK, Kumar BS, Satish R. Heritability of Thirty Cephalometric Parameters on Monozygotic and Dizygotic Twins: Twin Study Method. J Contemp Dent Pract 2013; 14(2):304-311.
Influence of Artificial Aging in Marginal Adaptation of Mixed Class V Cavities
Authors: Tonetto Mateus Rodrigues , de Andrade Marcelo Ferrarezi , Pinto Shelon Cristina Souza , Borges Alvaro Henrique , Lima Darlon Martins , Bandéca Matheus Coelho , de Oliveira Barud Hélida Gomes , de Campos Edson Alves
Published: June 2013

The aim of this study was to investigate whether the artificial aging by thermal cycling had influenced the marginal adaptation of class V restorations with/without chlorhexidine application in the bond process. Twelve intact human third molars were used. Class V cavity preparations were performed on the buccal surface and the teeth received 35% phosphoric acid-etching procedure (Ultradent Products Inc., South Jordan, Utah, USA). Subsequently, the samples were divided in two groups: Untreated acid-etched dentin and chlorhexidine application as an adjunct in the bond process. The adhesive Single Bond 2 (3M ESPE, St. Paul, MN, USA) was used after 2% chlorhexidine application, and the restorations were performed with FiltekTM Z350 XT (3M ESPE) composite resin. The specimens were submitted to artificial aging by thermal cycling with 3,000 cycles. Analyzes were performed on scanning electron microscopy using replicas of marginal adaptation in percentage of continuous margin before and after the artificial aging. The data were analyzed by paired test and the results showed statistically significant differences in the percentage of continuous margin with/without chlorhexidine treatment before and after thermal cycling. This study concluded that the artificial aging by thermal cycling influenced the marginal adaptation of mixed class V composite restorations.

How to cite this article

Tonetto MR, Bandéca MC, de Oliveira Barud HG, Pinto SCS, Lima DM, Borges AH, de Campos EA, de Andrade MF. Influence of Artificial Aging in Marginal Adaptation of Mixed Class V Cavities. J Contemp Dent Pract 2013;14(2):316-319.
Multidisciplinary Management of a Child with Severe Open Bite and Amelogenesis Imperfecta
Authors: Millet Catherine , Duprez Jean-Pierre
Published: June 2013

Aim

To present a case of multidisciplinary management and fixed rehabilitation of a young girl with amelogenesis imperfecta (AI), a severe open bite and occlusal instability.

Background

AI is a genetic disorder characterized by enamel malformations, disturbances in tooth eruption and significant attrition. Early diagnosis is essential, since rapid breakdown of tooth structure may occur, giving rise to acute symptoms and complicated treatment. As AI is frequently accompanied by unesthetic appearance, open bite deformity and malocclusion, a multidisciplinary approach is often required.

Case report

This clinical report describes the condition and presents the case of a 10-year-old girl with hypocalcified form of AI. Orthodontic treatment and orthognathic surgery were performed as part of the prosthetic treatment plan to achieve acceptable and durable results. They consisted of correcting class II, posterior crossbite and anterior open bite with a fixed orthodontic appliance, Lefort I osteotomy, bilateral mandibular ramus osteotomy and genioplasty. Prosthodontics treatment consisted of metal-ceramic crowns with low-fusing ceramic for good long-term results. No deterioration in the rehabilitation was found after 5 years of follow-up.

Conclusion

Complete restoration of severe AI is a long and complex process generally extending over several years.

Clinical significance

This article shows the important role of interdisciplinary approach to treating a patient with AI over a period of 8 years.

How to cite this article

Millet C, Duprez JP. Multidisciplinary Management of a Child with Severe Open Bite and Amelogenesis Imperfecta. J Contemp Dent Pract 2013;14(2): 320-326.
Interdisciplinary Treatment of an Adolescent with Unilateral Cleft Lip and Palate
Authors: Sudhakar P , Adusumilli Sai Prakash , Mummidi Bhaskar , Reddy KV Baburam , Rao CH Hanumantha , Raju BH V Rama Krishnam
Published: June 2013

Aim

The present case report describes the importance of interdisciplinary approach and gives an understanding on management of an adolescent with unilateral cleft lip and palate.

Background

Failure of fusion between medial nasal process and maxillary process or between the palatal process leads to the formation of clefts. Clefts are result of genetic or environmental factors or a combination of both. Common dental problems associated with clefts includes anterior and posterior crossbites, hypodontia, malformation and abnormal eruption pattern.

Case report

A girl, aged 15 years reported with a chief complaint of unesthetic appearance of her maxillary anterior teeth. She had unilateral cleft lip and palate and had received cheiloplasty and palatoplasty when she was in young age and rhinoplasty when she was 14 years of age. At pretreatment evaluation, she had concave profile with maxillary arch constriction and oroantral fistula and mesially tipped maxillary left canine.

Conclusion

This patient's treatment was unconventional, but it was successful in significantly improving her masticatory function and smile, along with favorable dental and facial results. Generalized esthetics and function were significantly improved in this patient without orthognathic surgery, and treatment results were stable 3 years after the appliance removal.

Clinical considerations, sequencing of treatment phases as shown in this case report can be utilized while treating an adolescent with cleft lip and palate.

Clinical significance

If the skeletal discrepancy is mild and esthetic concerns are minimal, dental compensation by orthodontic treatment alone might be recommended. The cephalometric analysis and prediction tracings provide further information for deciding whether a patient can be treated by orthodontics alone, or by orthodontics and an orthognathic surgical procedure.

A change in axial inclination of the teeth can camouflage the skeletal relationship adequately. However, one should be cautious in a growing patient, because he or she might outgrow the dental correction so that ultimately skeletal surgery would be indicated.

How to cite this article

Adusumilli SP, Sudhakar P, Mummidi B, Reddy KVB, Rao CHH, Raju BHVRK. Interdisciplinary Treatment of an Adolescent with Unilateral Cleft Lip and Palate. J Contemp Dent Pract 2013;14(2):332-338.
Sialolithiasis in the Duct of Submandibular Gland: A Case Report in Patient with Epidermolysis Bullosa
Authors: Primo Bruno Tochetto , da Costa Delson João , Stringhini Diego José , Rebellato Nelson Luis Barbosa , de Moraes Rafaela Scariot , Müller Paulo Roberto , Carneiro Vera Lúcia
Published: June 2013

Aim

To describe the options of treatment to remove a sialolith associated with the submandibular gland duct in a patient with epidermolysis bullosa (EB).

Background

Treatment of patients with EB is very complex and involves a multidisciplinary team. This condition is characterized by a spectrum of blistering and mechanical fragility of the skin. One main feature of this disease is the esophageal constriction and possible constriction to the submandibular duct. This alteration may induce the formation of calculi in this duct, which is called sialolith. Once the sialolith obliterates the trajectory of the duct this will lead to a sialolithiasis. The calculi have to be removed.

Case report

Seventeen years old female patient with dystrophic EB developed a sialolith at the submandibular duct. She has a limited mouth opening and her tongue was collapsed with mouth floor. The first choice of treatment was the lithotripsy, once this procedure is less invasive and a surgical remove could worse the collapsed tongue. She was with acute pain and with a great augmentation in the submandibular area. Once the patient was debilitated and has difficult to swallow she invariably needed to be hospitalized in order to receive intravenous medication. During the hospitalization the sialolith could be seen through the opening of the duct and the calculi was removed with local anesthesia.

Conclusion

The treatment of sialolithiasis usually does not present major challenges, nevertheless if the sialolithiasis is associated with EB, the treatment became an extremely challenge. In this particular case the option of treatment was the less invasive.

Clinical relevance

This case report has an enormous clinical relevance once there is no protocol to treat patients with EB and buccal diseases.

How to cite this article

Primo BT, da Costa DJ, Stringhini DJ, Rebellato NLB, de Moraes RS, Müller PR, Carneiro VL. Sialolithiasis in the Duct of Submandibular Gland: A Case Report in Patient with Epidermolysis Bullosa. J Contemp Dent Pract 2013;14(2):339-344.
Endodontic Treatment of a Maxillary Central Incisor with Two Roots
Authors: Jafarzadeh Hamid , Maghsoudlou Amir , Forghani Maryam
Published: June 2013

Aim

This clinical report presents a rare case of maxillary central incisor with two separate roots.

Background

Unusual morphology of the roots and root canals may exist in any tooth. Recognition of the dental anatomy and its variations is necessary for successful endodontic therapy. It is well known that maxillary incisors are usually single-rooted teeth.

Case report

The root canals were instrumented with conventional hand files and Gates Glidden and obturated by using the lateral technique. Recall radiograph after 1 year shows the healing process of the preoperative apical periodontitis.

Conclusion and clinical significance

Clinicians should be aware of unexpected root canal morphology when performing root canal therapy. The present case demonstrated the importance of accurate preoperative radiograph and adequate access preparation.

How to cite this article

Maghsoudlou A, Jafarzadeh H, Forghani M. Endodontic Treatment of a Maxillary Central Incisor with Two Roots. J Contemp Dent Pract 2013;14(2):345-347.
Esthetic Dentistry in Patients with Bilaterally Missing Maxillary Lateral Incisors: A Multidisciplinary Case Report
Authors: Reddy KV Baburam , Rao CH Hanumantha , Mummidi Bhaskar , Prasanna A Laxmi , Vijay M , Raju MAKV
Published: June 2013

Congenitally missing maxillary lateral incisors pose a difficult esthetic and treatment planning problem for clinicians. Age, location, space limitations, alveolar ridge deficiencies, uneven gingival margins, occlusion and periodontal factors often necessitate an interdisciplinary approach. Over the last several decades, dentistry has focused various treatment modalities for replacement of missing teeth. Treatment plans for patients with missing maxillary lateral incisors have traditionally included either space closure or space reopening. To remove healthy tooth structure of adjacent teeth to replace a tooth, for some patients and dentists, is a very aggressive treatment option which eliminates the option of three unit bridges. Removable partial dentures are also not preferred for its bulkiness and reduced esthetics. Presently, the single implant supported crown is a predictable method of tooth replacement in adolescents. The aim of this case report is to provide a conservative method for the management of bilateral missing lateral incisor.

How to cite this article

Mummidi B, Rao CHH, Prasanna AL, Vijay M, Reddy KVB, Raju MAKV. Esthetic Dentistry in Patients with Bilaterally Missing Maxillary Lateral Incisors: A Multidisciplinary Case Report. J Contemp Dent Pract 2013;14(2):348-354.
Isotopic composition of water-soluble nitrate in bulk atmospheric deposition at Dongsha Island: sources and implications of external N supply to the northern South China Sea
Authors: Yang J.-Y. T. , Hsu S.-C. , Dai M. , Hsiao S. S.-Y. , Kao S.-J.
Published: June 2013

Abstract. Increased reactive nitrogen (Nr, NO3− + NH4+ + dissolved organic nitrogen) emission from Asian continent poses profound threats on ecosystem safety from terrestrial throughout the ocean proper. To diagnose the sources of atmospheric Nr input and quantify its influence on marine nitrogen cycle of the South China Sea (SCS), an oligotrophic marginal sea adjacent to the emission hotspot China, we conducted measurements of dual isotopes of water-soluble nitrate (δ15NNO3 and δ18ONO3) and concentrations of major ions for bulk atmospheric deposition collected from Dongsha Island off south China. The δ15NNO3 and δ18ONO3 for bulk deposition ranged from −7.5‰ to +3.9‰ and ∼ +17‰ to +88‰, respectively. A relatively uniform low δ15NNO3 and high δ18ONO3 endmember were observed in winter. Non-sea-salt sulfate/calcium (nssSO42− and nssCa2+) peaked as the increasing nitrate depositional flux (one exception caused by typhoon), implying a pollution source of nitrate during high deposition. Meanwhile, the flux-weighted average of δ15NNO3 was −2.7± 2.3‰, resembling the isotopic signature of fossil fuel combustion in inland China. More variable dual isotopic values observed in July and September suggest relatively dynamics sources and conversion chemistry. During the period affected by the peripheral circumfluence of Typhoon Fanapi, a high nitrate deposition with uniform isotopic composition (δ15NNO3 of ~ −0.5‰ and δ18ONO3 of ∼ +19‰) was observed accompanying with low terrestrial constituents such as dust and pollutants (e.g. nssSO42− and nssCa2+). This high nitrate deposition was likely a natural endmember sourced from lightning. The summarized total atmospheric Nr deposition (AND) is ∼ 50 mmol N m−2 yr−1. If without this additional AND fertilization, CO2 release (currently 460 ± 430 mmol C m−2 yr−1) from the SCS would be doubled. Our study demonstrates that AND may serve as an important external Nr supply to the SCS yet difficult to separate from N-fixation (−2‰ to 0‰) due to isotopic similarity and high N : P ratio. More studies related to isotopic composition of nitrogen speciation and their relative contributions as well as the role of typhoon-induced input to AND are required.
Agricultural peat lands; towards a greenhouse gas sink – a synthesis of a Dutch landscape study
Authors: Schrier-Uijl A. P. , Kroon P. S. , Hendriks D. M. D. , Hensen A. , Van Huissteden J. C. , Leffelaar P. A. , Berendse F. , Veenendaal E. M.
Published: June 2013

Abstract. It is generally known that managed, drained peatlands act as carbon sources. In this study we examined how mitigation through the reduction of management and through rewetting may affect the greenhouse gas (GHG) emission and the carbon balance of intensively managed, drained, agricultural peatlands. Carbon and GHG balances were determined for three peatlands in the western part of the Netherlands from 2005 to 2008 by considering spatial and temporal variability of emissions (CO2, CH4 and N2O). One area (Oukoop) is an intensively managed grass-on-peatland, including a dairy farm, with the ground water level at an average annual depth of 0.55 m below the soil surface. The second area (Stein) is an extensively managed grass-on-peatland, formerly intensively managed, with a dynamic ground water level at an average annual depth of 0.45 m below the soil surface. The third area is an (since 1998) rewetted former agricultural peatland (Horstermeer), close to Oukoop and Stein, with the average annual ground water level at a depth of 0.2 m below the soil surface. During the measurement campaigns we found that both agriculturally managed sites acted as carbon and GHG sources but the rewetted agricultural peatland acted as a carbon and GHG sink. The terrestrial GHG source strength was 1.4 kg CO2-eq m−2 yr−1 for the intensively managed area and 1.0 kg CO2-eq m−2 yr−1 for the extensively managed area; the unmanaged area acted as a GHG sink of 0.7 kg CO2-eq m−2 yr−1. Water bodies contributed significantly to the terrestrial GHG balance because of a high release of CH4 and the loss of DOC only played a minor role. Adding the farm-based CO2 and CH4 emissions increased the source strength for the managed sites to 2.7 kg CO2-eq m−2 yr−1 for Oukoop and 2.1 kg CO2-eq m−2 yr−1 for Stein. Shifting from intensively managed to extensively managed grass-on-peat reduced GHG emissions mainly because N2O emission and farm-based CH4 emissions decreased. Overall, this study suggests that managed peatlands are large sources of GHG and carbon, but, if appropriate measures are taken they can be turned back into GHG and carbon sinks within 15 yr of abandonment and rewetting.
Subcritical water extraction to isolate kinetically different soil nitrogen fractions
Authors: Sleutel S. , Kader M. A. , Demeestere K. , Walgraeve C. , Dewulf J. , De Neve S.
Published: June 2013

Abstract. Soil organic N is largely composed of inherently biologically labile proteinaceous N and its persistence in soil is mainly explained by stabilization through binding to minerals and other soil organic matter (SOM) components at varying strengths. In order to separate kinetically different soil N fractions we hypothesize that an approach, which isolates soil N fractions on the basis of bonding strength is required, rather than employing chemical agents or physical methods. We developed a sequential subcritical water extraction (SCWE) procedure at 100 °C, 150 °C and 200°C to isolate SOM fractions. We assessed these SCWE N fractions as predictors for aerobic and anaerobic N mineralization measured from 25 paddy soil cores in incubations. SCWE organic carbon (SCWE OC) and N (SCWE N) increased exponentially with the increase of temperature and N was extracted preferentially over OC. The efficiency of SCWE and the selectivity towards N were both lower in soils with increasingly reactive clay mineralogy. The 100–150 °C SCWE N and the 100 °C + 100–150 °C SCWE N correlated slightly better with the aerobic N mineralization than soil N content. The resulting explained percentages (46–49%) are, however, too small to allow accurate fertilizer recommendations. No correlations were found between the SCWE fractions and anaerobic N mineralization rate and consequently alternative driving factors should be looked for. Nonetheless, perhaps SCWE does, still hold potential to separate kinetically different SOM pools from upland soils, in which the bio-availability of N is more likely to be a key constraint in the N mineralization process. This in contrast to the studied paddy soils, in which N mineralization appeared to be largely decoupled from SOM quantity and quality or its availability, perhaps due to an overriding control of abiotic factors on the anaerobic N mineralization process.
Evolving water science in the Anthropocene
Authors: Savenije H. H. G. , Hoekstra A. Y. , van der Zaag P.
Published: June 2013

Abstract. This paper reviews the changing relation between man and water since the industrial revolution, the period that has been called the Anthropocene because of the unprecedented scale at which humans have altered the planet. We show how the rapidly changing reality urges us to continuously improve our understanding of the complex interactions between man and the water system. The paper starts with demonstrating that hydrology and the science of water resources management have played key roles in human and economic development throughout history; yet these roles have often been marginalised or obscured. Knowledge on hydrology and water resources engineering and management helped to transform the landscape, and thus also the very hydrology within catchments itself. It is only fairly recent that water experts have become self-conscious of such mechanisms, exemplified by several concepts that try to internalise them (integrated water resources management, eco-hydrology, socio-hydrology). We have reached a stage where a more systemic understanding of scale interdependencies can inform the sustainable governance of water systems, using new concepts like precipitationsheds, virtual water transfers, water footprint and water value flow.
Seasonal evolution of snow permeability under equi-temperature and temperature-gradient conditions
Authors: Domine F. , Morin S. , Brun E. , Lafaysse M.
Published: June 2013

Abstract. The permeability K of snow to air flow affects the transfer of energy, water vapor and chemical species between the snow and the atmosphere. Yet today little is known of the temporal evolution of snow permeability as a function of metamorphic regime. Furthermore, our ability to simulate snow permeability over the seasonal evolution of a snowpack has not been tested. Here we have measured the evolution of snow permeability in a subarctic snowpack subject to high temperature-gradient (TG) metamorphism. We have also measured the evolution of the same snowpack deposited over tables so that it evolved in the equi-temperature (ET) regime. Permeability varies in the range 31 × 10–10 (ET regime) to 650 × 10–10 m2 (TG regime). Permeability increases over time in TG conditions and decreases under ET conditions. Using measurements of density ρ and of specific surface area (SSA), from which the equivalent sphere radius r is determined, we show that the equation linking SSA, density ρ and permeability, K = 3.0 r2 e(–0.013 ρ) (with K in m2, r in m and ρ in kg m−3) obtained in a previous study adequately predicts permeability values. The detailed snowpack model Crocus is used to simulate the physical properties of the TG and ET snowpacks. For the most part, all variables are well reproduced. Simulated permeabilities are up to a factor of two greater than measurements for depth hoar layers, which we attribute to snow microstructure, as the aerodynamic properties of hollow depth hoar crystals are different from those of spheres. Finally, the large difference in permeabilities between ET and TG metamorphic regimes will impact atmosphere-snow energy and mass exchanges and these effects deserve consideration in predicting the effect of climate change on snow properties and snow-atmosphere interactions.
Feedbacks and mechanisms affecting the global sensitivity of glaciers to climate change
Authors: Marzeion B. , Jarosch A. H. , Gregory J. M.
Published: June 2013

Abstract. Mass loss by glaciers has been an important contributor to sea level rise in the past and is projected to contribute a substantial fraction of total sea level rise during the 21st century. Here, we use a model of the world's glaciers in order to quantify equilibrium sensitivities of global glacier mass to climate change, and to investigate the role of changes in glacier hypsometry for long term mass changes. We find that 21st century glacier mass loss to a~large degree is governed by the glaciers responding to 20th century climate change. This limits the influence of 21st century climate change on glacier mass loss, and explains why there are relatively small differences in glacier mass loss under greatly different scenarios of climate change. Because of the geographic distribution of glaciers, both temperature and precipitation anomalies experienced by glaciers are vastly stronger than on global average. The projected increase in precipitation partly compensates for the mass loss caused by warming, but this compensation is negligible at higher temperature anomalies since an increasing fraction of precipitation at the glacier sites it liquid. Loss of low-lying glacier area, and more importantly, eventual complete disappearance of glaciers, strongly limit the projected sea level contribution from glaciers in coming centuries. The adjustment of glacier hypsometry to changes in the forcing reduces the sensitivity of global glacier mass to changes in global mean temperature by a factor of two to three. This result is a second reason for the relatively weak dependence of glacier mass loss on future climate scenario, and helps explain why glacier mass loss in the first half of the 20th century was of the same order of magnitude as in the second half of the 20th century, even though the rate of warming was considerably smaller.
Parameter and state estimation with a time-dependent adjoint marine ice sheet model
Authors: Goldberg D. N. , Heimbach P.
Published: June 2013

Abstract. To date, assimilation of observations into large-scale ice models has consisted predominantly of time-independent inversions of surface velocities for basal traction, bed elevation, or ice stiffness, and has relied primarily on analytically-derived adjoints of diagnostic ice velocity models. To overcome limitations of such "snapshot" inversions, i.e. their inability to assimilate time-dependent data, or to produce initial states with minimum artificial drift and suitable for time-dependent simulations, we have developed an adjoint of a time-dependent parallel glaciological flow model. The model implements a hybrid shallow shelf-shallow ice stress balance, involves a prognostic equation for ice thickness evolution, and can represent the floating, fast-sliding, and frozen bed regimes of a marine ice sheet. The adjoint is generated by a combination of analytic methods and the use of algorithmic differentiation (AD) software. Several experiments are carried out with idealized geometries and synthetic observations, including inversion of time-dependent surface elevations for past thicknesses, and simultaneous retrieval of basal traction and topography from surface data. Flexible generation of the adjoint for a range of independent uncertain variables is exemplified through sensitivity calculations of grounded ice volume to changes in basal melting of floating and basal sliding of grounded ice. The results are encouraging and suggest the feasibility, using real observations, of improved ice sheet state estimation and comprehensive transient sensitivity assessments.
Identificación y descripción de síntomas de los principales patógenos asociados al cultivo de marañón (Anacardium occidentale L.) orgánico y convencional, en león, Nicaragua
Authors: Jiménez-Martinez Edgardo , Gómez-Martinez Jorge
Published: June 2013

El presente estudio se realizó con el objetivo de identificar y describir los principales agentes causales de daño asociados al cultivo de marañón orgánico y convencional. Este estudio se realizó durante el período Julio 2009 a Marzo del 2010, en la comarca Chacraseca, del departamento de León. Mediante muestreos sistemáticos se evaluó la incidencia y severidad de estos agentes en el dosel delos árboles, para ello se seleccionaron cinco sitios fijos de muestreos en parcelas orgánicas y convencionales. Se colectaron muestras de hojas con signos y síntomas de posibles enfermedades, las muestras se llevaron al laboratorio de micología de la Universidad Nacional Agraria para su respectivo análisis patológico. Las variables evaluadas fueron: incidencia y severidad de manchas necróticas (Pestalotia sp) por ramas con hojas, Incidencia y severidad de manchas anaranjadas (Cephaleuros sp) por ramas con hojas, se midió el área bajo la curva de progreso de la enfermedad (ABCPE) de manchas necróticas y manchas anaranjadas. Los resultados fueron los siguientes: se identificó y se describió los síntomas de Pestalotiasp, y Cephaleurossp, estos resultaron ser los principales agentes causales de daño foliar en marañón, en este mismo estudio, se encontró mayor porcentaje de incidencia y severidad de manchas necróticas y manchas anaranjadas en parcelas con manejo orgánico que en parcelas con manejo convencional. La menor ABCPE para manchas necróticas se presentó en parcelas con manejo orgánico, y la menor ABCPE para manchas anaranjadas se presentó en parcelas con manejo convencional. DOI: http://dx.doi.org/10.5377/calera.v12i18.1119 Revista Científica Vol. 12. Nº 18, p. 01-08 / junio 2012
Insectos plagas y benéficos asociados al marañón (Anacardium occidentale L.) orgánico y convencional, en León, Nicaragua
Authors: Jiménez-Martínez Edgardo , Gómez-Martinez Jorge
Published: June 2013

El presente estudio se realizó durante el período julio 2009 a marzodel 2010, en la comarca Chacraseca, del departamento de León, Elobjetivo de este estudio fue identificar y describir la fluctuaciónpoblacional y el rol de los principales insectos plagas y benéficosasociados al marañón orgánico y convencional. Para llevar a caboeste estudio se seleccionaron tres fincas orgánicas y tres fincasconvencionales, en cada finca se seleccionó una parcela de 1 mz(0.7 ha), en cada parcela se seleccionaron cinco sitios fijos demuestreos, los muestreos se realizaron semanalmente a través decapturas manuales de insectos plagas e insectos benéficos del follaje.Los insectos colectados en el campo se llevaron al laboratorio deentomología de la Universidad Nacional Agraria para su respectivaidentificación. Las variables evaluadas fueron: Número de insectosHomóptera, Heteróptera, Coleóptera, Neuróptera, Díptera, eHymenóptera por familia. Los resultados fueron los siguientes:se encontró un mayor número de insectos plagas y benéficos enfincas de marañón orgánico que en convencional. Se identificóy se describió las fluctuaciones poblacionales de los insectosmiembros de las familias: Coreidae, Cicadellidae, Tenebrionidae,Chrysomelidae, Apidae, Formicidae, Dolichopodidae, y Vespidaeasociados a este cultivo, se encontró que las familias de insectosCicadellidae, Tenebrionidae, Chrysomelidae, Coccinellidae yFormicidae se presentaron con más frecuencia durante la épocade crecimiento vegetativo del cultivo, los insectos de la familiaDolichopodidae y Vespidae se presentaron con más frecuenciadurante la época de floración del cultivo; y los insectos de la familiaCoreidae y Apidae se presentaron con más frecuencia durante laépoca de fructificación del cultivo.DOI: http://dx.doi.org/10.5377/calera.v12i18.1120 Revista Científica Vol. 12. Nº 18, p. 09-17 / junio 2012
Alternativas de manejo contra el complejo mosca blanca (Bemisia tabaci gennadius)- geminivirus en el cultivo de tomate [Solanum lycopersicum L. = (Lycopersicum esculentum Mill.)] en Tisma, Masaya (2009) y Camoapa, Boaco (2010)
Authors: Cerda Kelving J , Jimenez-Martinez Edgardo
Published: June 2013

Mosca blanca (Bemisia tabaci) y los Geminivirus, son un serio problema para los productores de tomate en Nicaragua, este complejo afecta drásticamente los rendimientos del cultivo. Se han reportado diferentes tecnologías como solución al problema, tales como el uso de microinvernadero en la etapa semillero, uso de insecticidas sintéticos y prácticas culturales en la etapa de campo, sin embargo, la problemática de la plaga aún persiste. Con el propósito de identificar alternativas que disminuyan el daño ocasionado al medio ambiente y que sean económicamente viables, se estableció la investigación en la que se comparo el efecto de alternativas botánicas y químicas sobre la poblaciones de adultos B. tabaci, porcentaje de incidencia de virus, porcentaje de severidad de virus, rendimientos y análisis económico. El ensayo se estableció en dos ambientes, uno en Tisma (Masaya) en el periodo de Octubre a Diciembre del 2009 y el otro en Camoapa (Boaco) en los meses de Abril a Junio del 2010. El diseño utilizado fue un bloque completo al azar (BCA) en ambas localidades, los tratamientos evaluados fueron: Actara 25 WG (Thiametoxam); Engeo 24,7 SC (Thiametoxam+Lambda-Cihalotrina); macerado de hojas de madero negro (Gliricidia sepium); aceite vegetal+jabón líquido, chile (Capsicum sp)+ ajo (Allium sativum)+jabón y un testigo. Los resultados encontrados fueron los siguientes: los tratamientos con engeo, aceite vegetal + jabón líquido y hojas de madero negro registraron los promedios más bajo de mosca blanca por planta tanto en Tisma como en Camoapa. Los menores porcentajes de incidencia de virus y porcentaje de severidad del daño del virus fueron en engeo, aceite vegetal+jabón líquidos y madero negro. Los mejores rendimientos fueron registrados en engeo con promedios 26581- 18953 kg ha-1 y hojas de madero negro con promedios 25277-18107 kg ha-1 en Tisma (2009) y Camoapa (2010) respectivamente. El análisis económico demostró que engeo presentó una TRM de 457 % en Tisma (2009) y 696 % en Camoapa (2010).DOI: http://dx.doi.org/10.5377/calera.v12i18.1121 Revista Científica Vol. 12. Nº 18, p. 18-28 / junio 2012
Sistemas de manejo en café (Coffea arabica L.) y su efecto en la fertilidad del suelo y el rendimiento del café oro, Masatepe, Masaya
Authors: Luna-Rodríguez Fátima del Carmen , López-Mena Jaquelinne Guissel , Larios-González Roberto
Published: June 2013

El objetivo de este estudio fue comparar la influencia de tres sistemas de manejo en café sobre la fertilidad física, química y biológica del suelo y el rendimiento en café oro en el municipio de Masatepe, departamento de Masaya, Nicaragua en el período de julio del 2009 a enero del 2010. El tratamiento orgánico intensivo (OI) estuvo conformado por dos especies leguminosas como sombra, Inga laurina (Sw.) Willd (guaba) y Samanea saman (Jacq.) Merrill (genízaro), más aplicaciones por planta de 2.27 kg de pulpa de café (9 080 kg ha-1) e igual cantidad de gallinaza. El tratamiento orgánico extensivo (OE) involucra 2.27 kg de pulpa de café bajo las mismas especies arbóreas y un tercer tratamiento a plena exposición solar denominado convencional extensivo (CE) con aplicaciones por planta de 17 gramos (68 kg ha-1) de fertilizante 27- 9-18 en junio, 35 gramos (140 kg ha-1) de 12-30-10 en septiembre y 20 gramos (80 kg ha-1) de urea más 5 gramos (20 kg ha-1) de KCl en octubre. Se utilizó un arreglo unifactorial en diseño de bloques completo al azar, evaluándose las variables materia orgánica, nitrógeno total, capacidad de intercambio catiónico, porosidad, retención de humedad, y diversidad de la macrofauna del suelo. Se efectuaron un muestreo de suelo en el mes de julio de 2009 y otro en enero de 2010. Los resultados fueron analizados por diferencias mínimas significativas y en el caso de la macrofauna a través del índice de Shannon-Wiener. Los programas estadísticos utilizados fueron InfoStat profesional y Past versión 1.29, éste último para el análisis de la biodiversidad del suelo. No se encontraron diferencias estadísticas en los componentes de la fertilidad física y química del suelo, pero se observa una tendencia a disminuir en el sistema manejado convencionalmente. La mayor diversidad de macrofauna se presentó en los sistemas manejados orgánicamente. El rendimiento de café oro se comportó de forma variada, siendo mejor estadísticamente el sistema convencional extensivo en el primer ciclo agrícola (2002-2003), con un rendimiento de 305 kg ha-1. Posteriormente en el resto de los ciclos no se presentan diferencias significativas pero se observa un comportamiento alterno de mayor rendimiento entre el sistema orgánico intensivo y el convencional extensivo.DOI: http://dx.doi.org/10.5377/calera.v12i18.1122 Revista Científica Vol. 12. Nº 18, p. 29-36 / junio 2012
Comportamiento productivo de vacas lecheras alimentadas con Moringa oleifera fresco o ensilado: efecto sobre producción, composición y características organolépticas de leche y queso
Authors: Rodríguez-Pérez Rosaria De la Concepción , Reyes-Sánchez Nadir , Mendieta-Araica Bryan
Published: June 2013

Moringa oleifera fresca o ensilada, se comparó con una dieta control basada en Pennisetum purpureum cv CT-115 + concentrado comercial como dieta única para vacas lecheras. Se evaluó el efecto de las dietas experimentales sobre el consumo y la digestibilidad, la producción y composición de la leche, y las características organolépticas de leche y queso. Seis vacas lecheras fueron utilizadas en un experimento cuadrado latino 3x3, con dos repeticiones. Las dietas de Moringa fueron isocalóricas respecto a la dieta control. El consumo de materia seca (MS) de los tratamientos de Moringa fue significativamente mayor (P<0.05) que el control. Moringa fresca tuvo el mayor consumo (P<0.001) de materia orgánica (MO), proteína bruta (PB), fibra detergente neutra (FDN), fibra detergente ácido (FDA) en comparación con la dieta de control. Los mayores coeficientes de digestibilidad (P<0.05) se manifestaron en el tratamiento control respecto a los tratamientos de Moringa (fresca o ensilada), con la excepción de la digestibilidad de la PB. La producción de leche del tratamiento de Moringa ensilado fue ligeramente inferior (9%) respecto a los otros dos tratamientos. La composición de la leche fue similar entre todos los tratamientos. Sin embargo, la leche del tratamiento de Moringa fresca presentó un sabor y aroma a hierba, significativamente diferente (P<0.001) de los otros dos tratamientos, a pesar de que era normal en color y apariencia. No se observaron diferencias organolépticas entre la leche del tratamiento control y el tratamiento de ensilaje de Moringa. Igual comportamiento se encontró en el queso elaborado a partir de la leche de los tres tratamientos. El análisis financiero favorece a los tratamientos de Moringa. La conclusión es que el ensilaje de Moringa se puede utilizar para alimentar vacas lecheras en grandes cantidades para producir cantidades similares y misma producción de leche, características organolépticas. calidad de la leche que las dietas convencionales. DOI: http://dx.doi.org/10.5377/calera.v12i18.1124 Revista Científica Vol. 12. Nº 18, p. 45-51 / junio 2012