bluuebunny/crossref_metadata_2025_split huggingface dataset:
The climate footprint: a practical tool to address climate change
Authors: Janse T. , Wiers P. 
Published: August 2007

Waternet supplies clean and safe drinking water to the homes of almost one million Amsterdam citizens, and also collects and treats the resulting wastewater, ensuring its safe discharge back into the water system. Climate change poses a growing challenge. Firstly Waternet is affected by the consequences of climate change, such as longer periods of drought and heavier bursts of rainfall. Secondly, the company also plays a role in causing climate change, as emissions from the Amsterdam water chain contribute to global warming. This paper aims to focus attention on mitigation as an inseparable part of adaptation-programmes.
The Climate Footprint methodology is applied to the integrated Amsterdam water chain: from the point of withdrawing water from the surface/groundwater water system for drinking water production, to the point of returning the purified wastewater to the surface water/groundwater system. In-between, the water is pre-treated with chemicals, transported, purified by dune-filtration, again treated for drinking water quality, distributed over the area of Amsterdam, used in households and industries, collected from there by sewers and pumps, transported to purification plants and finally again treated with chemicals and purified to end with acceptable surface water quality.
The whole process generates CO2-emissions in three different ways:
Sewage treatment transforms the remains of human food consumption into CO2. These emissions do not originate from fossil fuels, but from food. They remain in a short carbon cycle and do not contribute to global warming. In fact, the sludge remaining from the purification plant is an important energy source. Transport and purification processes require energy; this results in direct emissions e.g. in the case of fuel or natural gas use, and indirect emissions in the case of electricity. The use of chemicals and materials for construction, transport systems, and all other facilities and services to keep the system running does require suppliers of these goods and services to consume energy and thus causes indirect emission.
An inventory of these three different types of emissions is made for the (about) 1990 situation, the 2004 situation, and prognosticated for the 2007 situation. The 2004 situation reveals a 0.16 ton CO2 equivalent emission per person. Compared to the worldwide 4 ton emission per person, this would mean a 4% contribution from the urban water system.
With all the improvements scheduled, a 50% elimination of greenhouse gas emissions looks attainable for the 2007 situation. Further possibilities for emission reductions may be found by talking to suppliers about the indirect emissions.
Financial Aid and Student Bargaining Power
Authors: Lang David M 
Published: August 2007

Abstract
To say that financial aid is a key component of the college admissions process is an understatement. For the student and her family, financial aid is a way to afford quality post-secondary education that otherwise may have been unobtainable. For the college, financial aid is a method to compete for the best and brightest students. For policymakers, financial aid is a subsidy for educational expenses where constituencies often differ over its merits. This research attempts to analyze the financial aid process by considering the ability of a student to act strategically. A game-theoretic model developed by Epple, Romano, Sarpca, and Sieg (2005) is utilized and evaluated using empirical evidence from the 1996 National Postsecondary Student Aid Study (NPSAS:96). It is shown that a student can maximize her financial aid offer by increasing the number of schools to which she has been accepted after controlling for ability, demographics, state fixed effects and institutional characteristics. A matching estimator to calculate average treatment effects and properly address endogeneity concerns.
Ideology, Inequality and Inequitable Trade Policies
Authors: Djerdjian Daron O 
Published: August 2007

Abstract
Does more wealth inequality lead to more inequitable trade policies? To answer this question, this study develops a political economy model of international trade theory and predicts that in a pro-worker regime, an increase in wealth inequality leads to more equitable trade policies. In a pro-capitalist regime, an increase in wealth inequality leads to more inequitable trade policies. Using cross-country data on political ideology, wealth inequality and different measures of trade policies, this paper finds empirical support for these predictions.
The 1990 Clean Air Act and the Implicit Price of Sulfur in Coal
Authors: Lange Ian , Bellas Allen S 
Published: August 2007

Abstract
Prior to implementation of the 1990 Clean Air Act Amendments (CAAA), many estimates of the marginal cost of SO2 abatement were provided to guide policy makers. Numerous studies estimated the marginal cost of abatement to be between $250 and $760 per ton, though permits initially traded well below $200 and remained below $220 until 2004. We use a fixed effects estimator and a hedonic price model of coal purchases in order to determine the implicit price of sulfur. Data on contract coal purchases are divided into regulatory regimes based on when the contract was signed or re-negotiated. We find that purchases by Phase I plants made under contracts signed or re-negotiated after the passage of the 1990 CAAA show an implicit price of SO2 of approximately $50 per ton, an amount much closer to the eventual permit price. The implicit market price of sulfur seems to have revealed better information than did the calculations of industry experts.
Optimal Contracts for Health Services in the Presence of Waiting Times and Asymmetric Information
Authors: Siciliani Luigi 
Published: August 2007

Abstract
This study presents a model of optimal contracting for health services in the presence of excess demand and waiting times. We assume that: i) hospitals differ in their demand for treatment; ii) potential demand is private information of the provider; iii) specialists can dump patients; iv) activity and waiting times are contractible. A separating equilibrium exists when it is optimal for the purchaser to contract more activity and longer waiting times to those hospitals with higher demand. Hospitals with low demand gain informational rents. A pooling equilibrium may also occur.
The Informational Value of Affirmative Action in College Admissions
Authors: Furstenberg Eric K 
Published: August 2007

Abstract
This article develops a theoretical model of college admissions to investigate the effects of banning affirmative action admissions policies on the efficiency of the admissions process. Previous work in this area has shown that prohibiting affirmative action causes inefficiency when college quality is an increasing function of diversity. This article identifies an additional reason why colleges and universities use racial preferences in admissions, setting aside explicit demands for diversity. In the theoretical model, the racial identity of the applicants is relevant information for making inferences about an applicant's true academic ability. Preventing admissions officers from using this information results in inefficient selection of applicants, even if diversity does not explicitly enter the objective of the university. Thus, affirmative action is justified solely on informational grounds.
Skeletal Anchorage for Orthodontic Correction of Severe Maxillary Protrusion after Previous Orthodontic Treatment
Authors: Tanaka Eiji , Nishi-Sasaki Akiko , Hasegawa Takuro , Nishio Clarice , Kawai Nobuhiko , Tanne Kazuo 
Published: August 2007

Abstract
The correction of a severe maxillary protrusion in an adult by distal movement of the maxillary molars has been one of the most difficult biomechanical problems in orthodontics. This article reports on the treatment of an adult case of severe maxillary protrusion and a large overjet treated with a skeletal anchorage system. A female patient, age 22 years and 3 months, complained of the difficulty of lip closure due to severe maxillary protrusion with a gummy smile. Overjet and overbite were +7.6 mm and −0.9 mm, respectively. She had a history of orthodontic treatment in which her maxillary first premolars were extracted. In order to conduct distal movement of the maxillary molars, anchor plates were placed in the zygomatic process. After achieving a Class I molar relationship, retraction and intrusion of the maxillary incisors were performed. After a 2-year treatment, an acceptable occlusion was achieved with a Class I molar relationship. Her convex facial profile with upper lip protrusion was considerably improved, and the lips showed less tension in lip closure. After a 2-year retention period, an acceptable occlusion was maintained without recurrence of maxillary protrusion, indicating a stability of the occlusion. The result of this treatment indicated that skeletal anchorage is of great importance as a remedy for achieving intrusion and retraction of the maxillary incisors in cases of severe maxillary protrusion with a patient who had previous orthodontic treatment.
Oral Breathing and Head Posture
Authors: Cuccia Antonino Marco , Lotti Maurizio , Caradonna Domenico 
Published: August 2007

Abstract
Objective: To determine the head posture and cephalometric characteristics in oral breathing children.
Materials and Methods: Lateral cephalograms taken in natural head posture of 35 oral breathing patients (OB) (mean age 8.8 ± 2.2 years SD; range 5–13 years) and of 35 patients with varied malocclusions and physiological breathing (PB) (mean age 9.7 ± 1.6 years SD; range 7–13 years) were examined.
Results: A Student's t-test showed that an increase in angles NSL/OPT (P = .000), NSL/CVT (P = .001), FH/OPT (P = .000), FH/CVT (P = .005), and NSL/VER (P = .000); a decrease in the distance MGP-CV1p (P = .0001); and a decrease in the angles MGP/OP (P = .000) and OPT/ CVT (P = .036) were found in the OB group. A low position of the hyoid bone (H-MP, P = .009), a major skeletal divergence (ANS-PNS/Go-Me, P = .000), and an increased value of the ANB angle (P = .023) were present in OB patients. To ascertain if the changes in posture were connected with posterior obstruction of the upper respiratory airways, the OB group was divided into two subgroups based on the distance Ad2-PNS being greater than or less than 15 mm. No significant differences were found between these two groups.
Conclusions: Our data suggest that OB children show greater extension of the head related to the cervical spine, reduced cervical lordosis, and more skeletal divergence, compared with PB subjects.
Duration and Anchorage Management of Canine Retraction with Bodily Versus Tipping Mechanics
Authors: Shpack Nir , Davidovitch Moshe , Sarne Ofer , Panayi Narchos , Vardimon Alexander D. 
Published: August 2007

Abstract
Objective: To compare tipping mechanics (TM) and bodily mechanics (BM) with respect to duration, angulation, and anchorage loss during canine retraction.
Materials and Methods: TM and BM brackets were bonded to the upper right and left canines, respectively, of 14 subjects requiring maxillary first premolar extractions. The upper canines were retracted with variable nickel titanium closed coil springs (F = 0.50 or 0.75 N) attached posteriorly to a Nance anchorage appliance through the first molars. Panoramic radiographs and dental casts were taken at five time points. Canine angulation was assessed with custom metallic jigs inserted into the vertical slots of the canine brackets prior to radiographic exposure.
Results: The canine crown contacted the second premolar after 102.2 ± 106 and 99.0 ± 80.0 days, and achieved root uprighting in 72.0 ± 31.3 and 37.2 ± 42.7 additional days with the TM and BM groups, respectively. Only the uprighting stage differed significantly between the two mechanics (P &lt; .05). During retraction, tooth angulation differed significantly (P &lt; .001) between the TM (6°) and BM (−0.8°) groups. Anchorage loss, as assessed by mesial molar movement, was 1.2 ± 0.3 mm and 1.4 ± 0.5 mm for the TM and BM groups, respectively.
Conclusions: Bodily canine retraction occurred faster (38 days) than tipping due to a shorter duration of root uprighting. Anchorage loss (17%–20%) was similar for both retraction methods, ie, maximum anchorage could not be provided by the Nance appliance. Both TM and BM brackets had inadequate rotational control of the retracted canine.
Dental Status and Orthodontic Treatment Needs of an 11-Year-Old Female Resident of Athens, 430 BC
Authors: Papagrigorakis Manolis J. , Synodinos Philippos N. , Baziotopoulou-Valavani Effie 
Published: August 2007

Abstract
This report presents the skeletal and dental features of “Myrtis”, an 11-year-old female resident of ancient Athens back in 430 BC. Her skeleton was unearthed in an archaeological excavation of a mass burial pit located in the outskirts of Kerameikos' ancient cemetery of Athens. “Myrtis” is believed to have been one of the numerous hapless victims of the Plague of Athens.
Her skull was found in relatively intact condition bearing her complete dentition corresponding to the mixed dentition stage. A complete dental and orthodontic diagnosis of Myrtis was conducted based on clinical examination, study of panoramic radiographs, and lateral cephalometric analysis of her skull. No significant dental pathology was reported pertaining to deciduous or permanent teeth of “Myrtis”. A Class II skeletal and dental malocclusion was observed. The ectopic labial eruption of the maxillary canines mesially to their retained deciduous predecessors, the ectopic distally directed eruption of a lower first premolar, and a unilaterally missing lower third molar were among the most interesting dental findings reported.
Conventional and High Intensity Halogen Light Effects on Water Sorption and Microhardness of Orthodontic Adhesives
Authors: Uysal Tancan , Basciftci Faruk Ayhan , Sener Yagmur , Botsali Murat Selim , Demir Abdullah 
Published: August 2007

Abstract
Objective: To test the null hypothesis that when the equivalent total light energy is irradiated to three orthodontic adhesive resins, there is no difference between the microhardness and water sorption values regardless of the curing light sources.
Materials and Methods: Samples were divided into six groups according to the combination of three orthodontic adhesives (Kurasper F, Light-Bond, Transbond XT) and two light intensities (quartz tungsten halogen [QTH] and high intensity quartz tungsten halogen [HQTH]). One half of each of the 40 samples of three adhesive pastes was polymerized for 20 seconds by a QTH light source, and the other half was polymerized for 10 seconds by a HQTH light source. Water sorption was determined and Vickers hardness was established with three measurements per sample at the top, center, and bottom. Statistical analysis was performed using two-way analysis of variance (ANOVA) with multiple comparisons (Tukey-HSD).
Results: Statistically significant differences were found among all adhesives for water sorption and hardness values cured with QTH and HQTH. The HQTH curing unit resulted in higher values than did the QTH. The highest water sorption values were observed for Kurasper F cured with HQTH and the lowest value was observed for Transbond XT cured with QTH. For microhardness Light-Bond cured with HQTH produced the highest values, and Transbond XT cured with QTH produced the lowest.
Conclusions: When the equivalent total light energy is irradiated to three orthodontic adhesive resins, there are significant differences between the microhardness and water sorption values cured with the QTH and HQTH light source. The null hypothesis is rejected.
Mandibular Asymmetry in Class II Subdivision Malocclusion
Authors: Kurt Gökmen , Uysal Tancan , Sisman Yildiray , Ramoglu Sabri Ilhan 
Published: August 2007

Abstract
Objective: To evaluate the condylar and ramal mandibular asymmetry in a group of patients with Class II subdivision malocclusion to identify possible gender differences between male and female subjects.
Materials and Methods: Mandibular asymmetry measurements (condylar, ramal, and condylar-plus-ramal asymmetry values) were performed on the panoramic radiographs of 80 subjects (34 male and 46 female). The study group consisted of 40 Class II subdivision patients (18 male and 22 female; mean age 14.53 ± 3.14 years). The control group consisted of 40 subjects with normal occlusion (16 male and 24 female; mean age 14.43 ± 3.05 years). The Kruskal-Wallis test was used to determine the possible statistically significant differences between the groups for condylar, ramal, and condylar-plus-ramal asymmetry index measurements. Identified differences between groups were further analyzed using the Mann-Whitney U-test at the 95% confidence interval (P &lt; .05).
Results: No gender-related difference was found for any of the asymmetry indices. Comparison of condylar, ramal, and condylar-plus-ramal asymmetry index values and gonial angle measurements for Class I and Class II sides in the Class II subdivision group and for right and left sides in the Class I group showed no statistically significant differences. However, the Class II subdivision group has longer values for condylar, ramal, and condylar-plus-ramal height measurements and only these differences were statistically significant (P &lt; .001).
Conclusions: Except for condylar ramal and condylar-plus-ramal height measurements, Class II subdivision patients have symmetrical condyles when compared to normal occlusion samples according to Habbet's mandibular asymmetry indices.
Cervical Vertebrae Anomalies—Incidental Findings on Lateral Cephalograms
Authors: Soni Priyavrat , Sharma Vineet , Sengupta Jaideep 
Published: August 2007

Abstract
Three cases of abnormal incidental findings on lateral cephalogram are presented. These patients reported for orthodontic consultation in their adolescence. While studying the patients' cephalograms, abnormal radiographic findings were discovered in their cervical vertebrae. Because the patients were asymptomatic, early diagnosis based on these radiographic findings made the patients aware of the situations. Lifestyle changes were instituted with specialist consultation in two patients to prevent or delay the onset of symptoms of an underlying pathology. Patients were educated about the likely future course of these findings. Specialist follow-up was advised to all the patients.
Distal Movement of Maxillary Molars Using a Lever-arm and Mini-implant System
Authors: Lim Seung-Min , Hong Ryoon-Ki 
Published: August 2007

Abstract
Recently, many studies have been reported on distal molar movement using temporary anchorage devices. However, the side effects of distal movement, such as distal tipping, rotation, or extrusion, are still unsolved. This article describes the use of the lever-arm and mini-implant system for controlled distal movement of maxillary molars and two clinical cases in which patients were treated with this system. Mini implants are needed to control the point of force application in the posterior area with no anchorage loss. When the length of the lever arm and the position of the mini implant are adjusted, the desired line of action of the distal force is determined with respect to the center of resistance of maxillary molars. The lever-arm and mini-implant system is useful not only for absolute anchorage, but also for three-dimensional control during distal movement of the upper molars.
Soft Tissue Profile in White Brazilian Adults with Normal Occlusions and Well-Balanced Faces
Authors: Scavone Helio , Zahn-Silva Wesley , do Valle-Corotti Karyna Martins , Nahás Ana Carla Raphaelli 
Published: August 2007

Abstract
Objective: To analyze anteroposterior soft tissue facial parameters for a sample of white Brazilian adults and to compare these measurements with the values proposed for white North American adults.
Materials and Methods: Facial profile photographs were taken of 59 white Brazilians (30 men and 29 women) with normal occlusions and balanced faces with ages ranging from 18 to 30 years. The independent Student's t-test (P &lt; .05) was used to compare the soft tissue parameters of the Brazilians with those of the North Americans.
Results: White Brazilian women presented a less protruded face compared with white American women except for the glabella region. White Brazilian women showed a smaller nasal projection, less protruded upper and lower lips, a more obtuse nasolabial angle, and a smaller projection of the B′ point and chin than white American women. Conversely, the two male groups demonstrated less evident soft tissue profile differences, with the exception of the nose projection, which was smaller in white Brazilian men than in white American men.
Conclusions: A universal standard of facial esthetic is not applicable to diverse white populations. Differences regarding the soft tissue profile features were found between white Brazilians and white Americans. These differences should be considered in the orthodontic/orthognathic surgery diagnosis and treatment plan for white Brazilians together with the patient's individual opinion and perception of beauty.
Occlusal Morphology 1 Year after Orthodontic and Surgical-Orthodontic Therapy
Authors: Dellavia Claudia , Ghislanzoni Luis Tomas Huanca , Peretta Redento 
Published: August 2007

Abstract
Objective: To evaluate morphologic characteristics of occlusion (contact points, contact areas, and frequency of contact) in clinically successful patients 1 year after orthodontic and surgical-orthodontic therapy followed by passive retention.
Materials and Methods: Twenty-two orthodontic and 18 surgical-orthodontic patients were analyzed. All patients were treated with standard edgewise technique by the same orthodontist. Contact points and areas were evaluated using a new method of digital image analysis of occlusal impressions. Polivinylsyloxan impressions were taken, scanned, and turned into gray-scale images. The physic relationship of light absorbance through the polivinylsyloxan for known thickness was calculated to determine contact areas (less than 50 μm of thickness) and near contact areas (less than 350 μm of thickness).
Results: The contact area was significantly larger in the orthodontic than in the surgical-orthodontic patients (Student's t-test, P &lt; .05). The surgical-orthodontic group had significantly fewer contact points than the orthodontic group only at 150 μm of thickness. In both groups of patients, the first molar had the largest contact surface. Occlusal support was distributed mainly in the posterior regions with an important role involving the first molars.
Conclusion: Surgical-orthodontic patients appear to have smaller contact surfaces and fewer contact points than orthodontic patients do. However, there were no differences in the number of teeth in contact with opposing teeth.