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This study marks the most comprehensive assessment of the overall impact of dropsondes on tropical cyclone (TC) forecasts to date. We compare two experiments to quantify dropsonde impact: one that assimilated and another that denied dropsonde observations. These experiments used a basin-scale, multi-storm configuration of the Hurricane Weather Research and Forecasting model (HWRF) and covered active North Atlantic basin periods during the 2017–2020 hurricane seasons. The importance of a sufficiently large sample size as well as thoroughly understanding the error distribution by stratifying results are highlighted by this work. Overall, dropsondes directly improved forecasts during sampled periods and indirectly impacted forecasts during unsampled periods. Benefits for forecasts of track, intensity, and outer wind radii were more pronounced during sampled periods. The forecast improvements of outer wind radii were most notable given the impact that TC size has on TC-hazards forecasts. Additionally, robustly observing the inner and near-core regionwas necessary for 64-kt-wind-radii forecasts. Yet, these benefitswere heavily dependent on the data assimilation (DA) system quality. More specifically, dropsondes only improved forecasts when the analysis used mesoscale error covariance derived from a cycled HWRF ensemble, suggesting that it is a vital DA component. Further, while forecast improvements were found regardless of initial classification and in steady-state TCs, TCs undergoing intensity change had diminished benefits. The diminished benefits during intensity change probably reflects continued DA deficiencies. Thus, improving DA-system quality and observing system limitations would likely enhance dropsonde impacts.

The contemporary literature suggests that a primary feature of recurrence of rotator cuff tear after arthroscopic repair is failure of tendon healing, which can occur for multiple reasons, including compromised tissue quality. Recently, the use of augmentation implants, grafts, or scaffolds has emerged as a strategy to address the issue of deficient rotator cuff tissue. A resorbable bio-inductive collagen implant (REGENETEN; Smith & Nephew, Andover, MA) has been shown to increase tendon thickness when applied in rotator cuff repair. This article presents an experienced surgeon’s tips for implanting this device. In addition, we review the current literature about this bio-inductive implant., Technique Video Video 1

This chapter calls for researchers to reconceptualize research quality from the perspective of its expected use, attending to power dynamics that influence how knowledge is defined, constructed, and validated through the research enterprise. Addressing these concerns when designing and conducting education research can yield more useful research evidence for building more equitable education systems. Anchored in scholarship on research utilization and methodological critiques, the chapter introduces a research quality framework that integrates relevance and rigor through five key dimensions of Research Worth Using: (1) relevance of question: alignment of research topics to practical priorities; (2) theoretical credibility: explanatory strength and coherence of principles investigated; (3) methodological credibility: internal and external credibility of study design and execution; (4) evidentiary credibility: robustness and consistency of cumulative evidence; and (5) relevance of answers: justification for practical application. This framework simultaneously uplifts the voices and needs of policymakers, practitioners, and community members, while elevating standards for excellence in education research. We call attention to the myriad ways in which the quality of evidence generated can be strengthened, before describing implications for curating and using research. We conclude by offering suggestions for applying and further developing the framework.

Osteochondral injuries commonly occur after lateral patellar instability events. Recognition and early intervention of displaced fragments is key to maintaining the viability of the fragment and congruency of the articular surface. Multiple fixation techniques exist for achieving stable fixation of displaced osteochondral lesions, including metal or bioabsorbable screws and all suture techniques. In this Technical Note, we describe a technique for internal fixation of a displaced osteochondral fragment of the lateral femoral condyle using knotless suture anchors. This technique affords minimally invasive restoration of the native anatomy with excellent stability of the fracture fragment, allowing early range of motion and ambulation., Technique Video Video 1 Intraoperative video demonstrating diagnostic arthroscopy with identification of an osteochondral fragment in the posterolateral recess of the knee and the corresponding defect along the lateral femoral condyle. Subsequent removal of fragment and evaluation on the back table. Debridement of the base of the osteochondral defect followed by marrow stimulation of the defect bed. Placement of knotless fiberTak anchors (Arthrex, Naples, FL) was followed by preparation of the fragment on the back table for knotless suture anchor fixation. The fixation limb is fed through the drill holes in the osteochondral fragment and a knotless interconnection between anchors is created. Gentle passage and final fixation of the osteochondral fragment follows.

Rhabdomyolysis in adults after anesthetic administration is uncommon in those without underlying risk factors. We present a 34-year-old female with history of severe gastroesophageal reflux disease (GERD), hypothyroidism, and migraines who developed severe rhabdomyolysis following an uncomplicated general anesthetic for esophagogastroduodenoscopy (EGD) and placement of Bravo esophageal pH monitor. The patient did not have any known risk factors for malignant hyperthermia, and halogenated agents were not used during the procedure. We speculate that the rhabdomyolysis was caused by the use of succinylcholine. Providers should be aware that even patients without known risk factors may be at risk for developing rhabdomyolysis, and it is important to remain vigilant about this potentially life-threatening complication.

The Hurricane Weather Research and Forecasting (HWRF) Model is a dynamical model that has shown annual improvements in its tropical cyclone (TC) track forecasts as a result of various modifications. This study focuses on an experimental version of HWRF, called the basin-scale HWRF (HWRF-B), configured with 1) a large, static outer domain to cover multiple TC basins and 2) multiple sets of high-resolution movable nests to produce forecasts for several TCs simultaneously. Although HWRF-B and the operational HWRF produced comparable average track errors for the 2011–14 Atlantic hurricane seasons, strengths of HWRF-B are identified and linked to its configuration differences. HWRF-B track forecasts were generally more accurate compared with the operational HWRF when at least one additional TC was simultaneously active in the Atlantic or east Pacific basins and, in particular, when additional TCs were greater than 3500 km away. In addition, at long lead times, HWRF-B average track errors were lower than for the operational HWRF for TCs initialized north of 25°N or west of 60°W, highlighting the sensitivity of TC track forecasts to the location of the operational HWRF’s outermost domain. A case study, performed on Hurricane Michael, corroborated these HWRF-B strengths. HWRF-B shows the potential to serve as an effective bridge between regional modeling systems and next-generational global efforts.

The Hurricane Weather Research and Forecasting Model (HWRF) was operationally implemented with a 27-km outer domain and a 9-km moving nest in 2007 (H007) as a tropical cyclone forecast model for the North Atlantic and eastern Pacific hurricane basins. During the 2012 hurricane season, a modified version of HWRF (H212), which increased horizontal resolution by adding a third (3 km) nest within the 9-km nest, replaced H007. H212 thus became the first operational model running at convection-permitting resolution. In addition, there were modifications to the initialization, model physics, tracking algorithm, etc. This paper compares H212 hindcast forecasts for the 2010–11 Atlantic hurricane seasons with forecasts from H007 and H3GP, a triply nested research version of HWRF. H212 reduced track forecast errors for almost all forecast times versus H007 and H3GP. H3GP was superior for intensity forecasts, although H212 showed some improvement over H007. Stratifying the cases by initial vertical wind shear revealed that the main weakness for H212 intensity forecasts was for cases with initially high shear. In these cases, H212 over- and under-intensified storms that were initially stronger and weaker, respectively. These results suggest the primary deficiency negatively impacting H212 intensity forecasts, especially in cases of rapid intensification, was that physics calls were too infrequent for the 3-km inner mesh. Correcting this deficiency along with additional modifications in the 2013 operational version yielded improved track and intensity forecasts. These intensity forecasts were comparable to statistical–dynamical models, showing that dynamical models can contribute to a decrease in operational forecast errors.

This paper provides an account of the performance of an experimental version of the Hurricane Weather Research and Forecasting system (HWRFX) for 87 cases of Atlantic tropical cyclones during the 2005, 2007, and 2009 hurricane seasons. The HWRFX system was used to study the influence of model grid resolution, initial conditions, and physics. For each case, the model was run to produce 126 h of forecast with two versions of horizontal resolution, namely, (i) a parent domain at a resolution of about 27 km with a 9-km moving nest (27:9) and (ii) a parent domain at a resolution of 9 km with a 3-km moving nest (9:3). The former was selected to be consistent with the current operational resolution, while the latter is the first step in testing the impact of finer resolutions for future versions of the operational model. The two configurations were run with initial conditions for tropical cyclones obtained from the operational Geophysical Fluid Dynamics Laboratory (GFDL) and HWRF models. Sensitivity experiments were also conducted with the physical parameterization scheme. The study shows that the 9:3 HWRFX system using the GFDL initial conditions and a system of physics similar to the operational version (HWRF) provides the best results in terms of both track and intensity prediction. Use of the HWRF initial conditions in the HWRFX model provides reasonable skill, particularly when used in cases with initially strong storms (hurricane strength). However, initially weak storms (below hurricane strength) posed special challenges for the models. For the weaker storm cases, none of the predictions from the HWRFX runs or the operational GFDL forecasts provided any consistent improvement when compared to the operational Statistical Hurricane Intensity Prediction Scheme with an inland decay component (DSHIPS).

Using the hurricane weather research and forecasting experimental modeling system (HWRFx), researchers examined the impact of increased model resolution on system performance in forecasting a select sample of tropical cyclones from the 2005 and 2007 hurricane seasons.

Doel: Het doel van deze studie is om na te gaan welke sporttakken de grootste bijdrage leveren aan langer durend arbeidsverzuim door sportblessures en welke letsels hier het meest verantwoordelijk voor zijn. Tevens wordt onderzocht in hoeverre er verschillen bestaan in verzuimduur en in hoeverre de aard van het werk hierop van invloed is.

The antibody response to Bartonella henselae has been studied in a number of mammals; however, the human response needs to be further studied. After natural infection, humans have antibody reactivity to a large number of B. henselae proteins. We used a proteomic approach to identify antigenic proteins of B. henselae to determine their capacity to elicit a human antibody response. Comparing patient sera by Western blot analysis demonstrated significant amounts of reactivity to B. henselae. The immunofluorescence assay (IFA)-positive sera identified several protein spots of interest. However, a consistent reactivity to a single spot by all sera was not observed. Three of these spots demonstrated reactivity in 71%, 64%, and 64% of positive sera tested with negligible reactivity to the negative sera. These proteins were identified as GroES, BepA, and GroEL. Most IFA-positive sera demonstrated reactivity to GroES, GroEL, and BepA. The usefulness of these proteins for a clinical serologic assay is discussed.

The objective of the work is the investigation of the relationship between the mechanisms of the short-term tensile strength and the creep rupture strength at testing temperatures more than 2/3 of the materials’ melting temperatures. The fundamental equations relating the materials tensile strength to the creep rupture strength at different temperatures and structural factors are obtained. These equations are derived by the use of the phenomenological and statistical thermodynamics of the crystalline lattice. The derived theoretical equation is used to determine creep on the bases of experimental values of the short-term test. The agreement between experimental and theoretical values of the creep is demonstrated. The presented results can be applied for prediction of the creep strength of new materials, particularly materials with enhanced mechanical properties.

This pilot study examined middle school and high school student performance on an online historical thinking assessment task. After their teachers received training in the use of digital historical archives, students from all groups engaged in historical thinking behaviors (e.g., observation, sourcing, inferencing, evidence, question-posing, and corroboration) in response to an open-ended document analysis exercise. The types of thinking they did are described, and differences between AP-level and non-AP students are discussed. Challenges teachers face in developing students’ historical thinking around visual documents are also discussed. Educators seeking to take advantage of digitized primary source documents need activities with clear curriculum linkages and small exercises that give students guidance in working with different kinds of documents (visual, textual, and audio). In addition, students and teachers need far more practice in learning to make meaning from primary source documents—in be...

Les employés de tous les niveaux de gouvernements ainsi que des services parapublics tels les hôpitaux et les écoles bénéficient au Canada de droits plus étendus à la négociation collective qu'aux États-Unis. Le contraste est particulièrement marqué en ce qui a trait au règlement des différends alors qu'une portion importante et grandissante d'employés de services publics au Canada bénéficient d'un droit à la grève reconnu par la loi.LA LÉGISLATION DU TRAVAIL ET LE SECTEUR PUBLICLes employés municipaux autres que les policiers et pompiers ont depuis plusieurs années été régis par les mêmes lois provinciales du travail que les ouvriers du secteur privé ; ceci leur a donné un droit de grève sans restriction. Les syndicats de policiers et pompiers, sauf quelques exceptions, ont accepté l'arbitrage obligatoire en vertu de leur propre constitution ou ils se le firent imposer par la loi. Alors que certaines provinces imposent l'arbitrage obligatoire plutôt que d'accorder le droit de grève aux enseignants et aux employés d'hôpitaux, d'autres provinces permettent à ces groupes professionnels, de même qu'aux employés municipaux de négocier collectivement sous l'empire de la législation du travail d'application générale, sans aucune restriction particulière. Les entreprises possédées par l'État de juridiction fédérale et de la plupart des provinces de même que plusieurs agences gouvernementales, sont également régies par la législation du travail d'application générale de sorte que leurs employés bénéficient des mêmes droits à la négociation collective que ceux qui sont accordés aux employés du secteur privé, y compris le droit de faire la grève.LES DISPOSITIONS À CARACTÈRE DÉCISOIRES AUX NIVEAUX SUPÉRIEURS DE GOUVERNEMENTSLe débat qui se déroule présentement au Canada quant à la négociation dans le secteur public et particulièrement quant aux modes de règlement des différends se situe présentement au niveau du domaine d'emploi du secteur public dans lequel un niveau supérieur de gouvernement est partie à la négociation collective. Sauf en Saskatchewan où les employés du gouvernement ont été régis par la législation du travail d'application générale depuis 1944, la négociation collective véritable pour les fonctionnaires fédéraux et provinciaux existe depuis moins de 10 ans. En 1965, le gouvernement du Québec a devancé les autres provinces et le gouvernement fédéral en accordant à ses fonctionnaires tous les droits à la négociation collective y compris le droit à la grève. Le gouvernement fédéral suivit en 1967 et le Nouveau-Brunswick fit de même en 1968. Même si ces juridictions sont les seules dans lesquelles les gouvernements permettent aux employés de faire la grève, toutes les autres provinces ont abandonné de façon formelle le pouvoir d'imposer un règlement en faveur de l'arbitrage obligatoire, ou bien sont sur le point de le faire. Le Manitoba s'est engagé à donner le droit de grève aux employés du gouvernement d'ici une année. On peut s'attendre à ce que la Colombie Britannique fasse de même sous peu. Même si les employés de certains niveaux supérieurs du gouvernement bénéficient maintenant du droit à la grève, il est clair qu'aucun consensus n'a été atteint en principe ou en pratique sur la procédure à suivre en cas d'impasse. La Saskat-chewan est la seule juridiction qui ne fait aucune distinction quant aux procédures de règlement des différends entre le secteur privé et le secteur public.La loi fédérale exige que les employés du gouvernement choisissent entre deux méthodes de règlement des différends, l'arbitrage obligatoire ou le droit à la grève, avant que les négociations puissent débuter. Un agent négociateur qui choisit le droit de grève devra accepter que les services essentiels soient maintenus durant la grève. Ces services essentiels seront maintenus par des employés désignés par la Commission des relations de travail dans la fonction publique conformément à l'accord des parties ou, à défaut d'accord, à sa propre décision. Cette commission est un organisme tripartite établi de façon permanente par la législation fédérale pour administrer les mécanismes de règlement des différends en plus d'exercer ses responsabilités quant à l'accréditation des agents négociateurs, le renvoi des griefs à l'arbitrage, etc. Le caractère indépendant de cette commission élimine les situations de conflit d'intérêts qui peuvent se produire lorsqu'un gouvernement, qui est lui-même partie à un différend, nomme le conciliateur ou l'arbitre.La province du Nouveau-Brunswick a adopté la plupart des aspects de la législation fédérale. Toutefois, alors que la loi fédérale exige que l'agent négociateur choisisse entre la conciliation et l'arbitrage avant de commencer les négociations, cette décision peut être prise en tout temps au Nouveau-Brunswick et peut être modifiée au cours des négociations.Le Québec accorde aux employés des services publics le droit à la grève, sous réserve d'une suspension de 80 jours de l'exercice du droit de grève lorsque les services essentiels sont en jeux. Cette suspension est obtenue au moyen d'une injonction de la cour, mais de telles injonctions ont donné lieu à des outrages aux tribunaux, en maintes occasions. Alors que la Saskatchewan, le Nouveau-Brunswick et le gouvernement fédéral permettent que l'arbitrage soit substitué à l'exercice du droit de grève, le Québec ne permet pas à une tierce partie de prendre la décision sur des questions qui touchent le budget provincial.CONSIDÉRATIONS DE PRINCIPELa principale particularité des négociations collectives dans le secteur public découle du fait que le gouvernement est l'employeur. De par ses fonctions législatives et exécutives, son obligation de protéger les deniers publics et d'assurer la protection des services essentiels, un gouvernement est un employeur d'une nature très différente de celle que l'on trouve dans le secteur privé. Mais même si les fonctions multiples du gouvernement et les pressions particulières du public imposent des contraintes inévitables sur les relations de travail, certains problèmes peuvent être réduits au minimum. L'un d'eux est le conflit d'intérêt qui peut survenir lorsqu'un gouvernement, qui est lui-même partie à un différend, administre les mécanismes de conciliation et d'arbitrage. En établissant un organisme indépendant pour ces fins, les lois du gouvernement fédéral et du gouvernement du Nouveau-Brunswick ont pour effet de soustraire les décisions quant à ces mécanismes de toute influence politique.La négociation collective est un phénomène relativement récent pour les niveaux supérieurs de gouvernement. Ainsi le manque de négociateurs expérimentés, particulièrement du côté gouvernemental, a quelques fois présenté de sérieux problèmes à la table de négociation. Les négociations ont parfois été rendues difficiles du fait que les négociateurs gouvernementaux ne possédaient pas toujours un mandat suffisant pour effectuer un règlement, particulièrement sur les clauses pécuniaires. Le gouvernement serait bien avisé de déléguer une autorité suffisante à des négociateurs expérimentés, non seulement pour effectuer un règlement mais aussi, ce qui est également important, pour inspirer aux négociateurs syndicaux la confiance qu'ils ont le pouvoir de le faire. Ceci aurait pour effet de faire disparaître certaines frustrations qui sont survenues dans la négociation du secteur public dans le passé.Alors que la tendance dans le secteur public au Canada est de réduire au minimum les délais de conciliation, sinon de les éliminer entièrement, le haut niveau d'intérêt public dans le règlement de différends dans les services publics, la nature essentielle de plusieurs de ces services et l'expérience limitée des parties quant à la négociation collective semblent être de bonnes raisons pour continuer et même prolonger les procédures de conciliation dans ce secteur.Mais qu'arrive-t-il en cas d'échec des négociations après que tous les mécanismes disponibles pour en arriver à une solution négociée ont été épuisés ? Certaines juridictions imposent alors l'arbitrage obligatoire des différends non résolus et d'autres permettent le choix entre l'arbitrage et la grève. Deux suggestions majeures ont été faites pour rendre l'arbitrage plus acceptable aux syndicats. La première consiste à confier l'administration du mécanisme d'arbitrage à une commission indépendante sur le modèle déjà établi par la loi fédérale et celle du Nouveau-Brunswick. La deuxième consiste à élargir le champ des questions qui peuvent être soumises à l'arbitrage.Le droit de grève demeure la question la plus litigeuse des relations de travail dans le secteur public et l'expérience tant canadienne qu'américaine démontre que des grèves peuvent et vont avoir lieu même si elles sont prohibées par la loi. Le problème del’applicabilité des lois ne doit pas être oublié lorsqu'une loi est à l'étude. Alors qu'il peut être difficile ou même injuste de priver la majorité des employés des services publics du droit qui est accordé aux employés du secteur privé, le problème crucial auquel font face les législateurs est celui de la définition des « services essentiels » et la garantie que ces services seront maintenus. Même si des dispositions à cet effet existent déjà au Québec, au Nouveau-Brunswick et au niveau fédéral pour assurer le maintien des services essentiels en cas de grève légale, la violation de ces dispositions durant la grève du secteur public au Québec et également par les techniciens en électronique de la fonction publique fédérale démontre que les sanctions légales actuellement prévues pour la non-observance de ces dispositions ne constituent pas un obstacle lorsque les employés sont suffisamment déterminés à les enfreindre. En se fondant sur cette expérience, il serait peut-être nécessaire de renforcer les sanctions pour non-observance. De plus, l'État peut toujours recourir à des mesures législatives spécifiques appropriées aux circonstances particulières de chaque cas. Les représentants élus du peuple ont le pouvoir ultime et la responsabilité de réagir à toute menace au bien-être du public., A brief overview of the current provisions for impasse resolution at all levels of public employment is followed by a more detailled discussion of policy and practice in jurisdictions that grant the right to strike to the employees of senior levels of government. Finally, the author tries to identify some of the problems that complicate the settlement of disputes in the public sector and considers the challenge and the prospects of resolving these problems in the light of the Canadian experience.

Water ice powder constitutes a potentially important manufacturing tool. Availability and cleanliness of this powder constitute its major advantage. It was shown that the ice particles could be used as an abrasive in the course of waterjet machining. Although the erosion potential of ice particles is inferior to that of the conventional abrasives, the environmental soundness of ice enables us to expend the use of the ice abrasive jets on food industry, medicine, precision machining, etc. The principal issue in the use of the ice abrasives is particles formation. Analysis of various technologies showed that an effective avenue in particle production is integration of the water freezing and ice decomposition. As the results, the desired flow rate of ice particles at the desired temperature and size distribution can be generated. The objective of the present paper is the experimental investigation of the production of ice particles. An experimental setup was constructed and used for particles fabrication at controlled conditions. The acquired information was applied for the analysis of the phenomena leading to the particles formation. As a result a hypothetical mechanism of the ice decomposition was suggested and validated. The experiments involving the decontamination of the electronic devices, semiconductors, fabric, leather, food products, polished metal, soft plastics, rusted auto parts, etc., were carried out in order to demonstrate the potential application of the ice blasting.

Phosphorylcholine (ChoP) is an antigenic component on the cell surface of many commensal and pathogenic bacteria that reside in the upper airway. In the present study, human ChoP-specific antibody was affinity-purified from pooled serum gamma globulin. This naturally acquired antibody, which is primarily of the immunoglobulin (Ig) G2 subtype, recognized ChoP on the lipoteichoic acid of Streptococcus pneumoniae and on the lipopolysaccharide of Haemophilus influenzae, 2 of the leading etiologic agents of infection involving the human respiratory tract. In in vitro killing assays, anti-ChoP IgG2 was effective against some clinical isolates of nontypeable H. influenzae and against isolates of several common serotypes of S. pneumoniae. Moreover, passively administered human anti-ChoP antibody protected mice against lethal challenge with a transparent isolate of S. pneumoniae type 6A. The effectiveness of human antibody to this conserved bacterial structure suggests that, if it can be manipulated to broaden its activity, it could function as a single vaccine antigen that targets multiple pathogens.

The objective of this study is to investigate the phenomena that occur in the course of energy injection into water at an extremely high rate. In this study energy was injected via the powder explosion. In the course of this study a numerical model was constructed and used for process investigation. The model describes powder combustion, energy exchange between combustion products and the water load, formation of the shock waves in the water and superposition of waves. It was assumed that powder combustion is a stationary process, and the description of this process was used to determine the variation of the pressure exerted on the water. The 1D space approximation was used for description of the dynamics of the water motion. The velocity and pressure fields were determined for a fixed instant of time. The characteristic method was used to relate the velocity and pressure distributions in the instants t and t+Δt. The pressure, velocity and density fields in the course of slug formation were calculated and used to evaluate the design characteristics of the device for water acceleration termed the water cannon.

This study was concerned with the use of the ice-air jet. It was demonstrated that at the optimal range of process conditions this jet constitutes a precision tool for selective material removal operations. Number of experiments was carried out in order to demonstrate this technology. Various electronic devices (computers, calculators, electronic games and watches, camera and lenses) were disassembled and electronic boards were contaminated by grease and metal powder. Then the boards were cleaned and reassembled. The computer, calculators and watches worked normally. Other experiments involved degreasing, depainting and deicing of liquid crystals, optical glass, removal emulsion from a film, etc. The feasibility of the damage free and pollution free decontamination of highly sensitive, highly countered surfaces was demonstrated. A low-cost ice-air cleaning will enable us to use it for processing large surfaces at a high rate. On-line degreasing of metal in the course of rolling or prior to machining illustrates this application. A generic environmentally friendly surface processing technology is emerging as the result of the presented study.

The years 1995 to 2000 experienced the highest level of North Atlantic hurricane activity in the reliable record. Compared with the generally low activity of the previous 24 years (1971 to 1994), the past 6 years have seen a doubling of overall activity for the whole basin, a 2.5-fold increase in major hurricanes (≥50 meters per second), and a fivefold increase in hurricanes affecting the Caribbean. The greater activity results from simultaneous increases in North Atlantic sea-surface temperatures and decreases in vertical wind shear. Because these changes exhibit a multidecadal time scale, the present high level of hurricane activity is likely to persist for an additional ∼10 to 40 years. The shift in climate calls for a reevaluation of preparedness and mitigation strategies.

Subjects studied lists of category exemplars with the highest and lowest frequency exemplars of those categories excluded. In Experiment 1, first and fifth grade children and college students falsely recognized pictures of related-high-frequency category exemplars more than related-low-frequency or unrelated exemplars. The magnitude of this false memory effect was comparable across all age groups and it increased after a 3-day delay. In Experiment 2, college students falsely recognized related-high-frequency word exemplars more than related-low-frequency or unrelated exemplars when exposure duration at study was 2 s or 20 ms per item. Similar to recent findings with converging associates (Seamon et al., 1998, even subjects who could not recognize list words following rapid exposure still demonstrated false memory of related-nonstudied category exemplars. These findings were discussed in terms of implicit activation and fuzzy trace interpretations of false memory.

We describe the development of an immunoglobulin M-specific enzyme-linked immunosorbent assay for the detection of an early antibody response to Bartonella henselae , the causative agent of cat scratch disease, bacillary angiomatosis, and endocarditis. This assay discriminates between B. henselae -positive and -negative patient samples with sensitivity and specificity values of 100% and 97.1%, respectively.

We report the results of an experimental study on stimulated and spontaneous emission from high-quality single-crystal GaN films grown on 6H-SiC and (0001) sapphire substrates in the temperature range of 300–700 K. We observed edge-emitted stimulated emission (SE) at temperatures as high as 700 K for samples grown on both SiC and sapphire substrates. The energy position of the SE and spontaneous emission peaks were shown to shift linearly to longer wavelengths with temperature and empirical expressions for the energy positions are given. We demonstrate that the energy separation between the spontaneous and SE peaks gradually increases from 90 meV at 300 K to 200 meV at 700 K indicating that an electron-hole plasma is responsible for the SE mechanism in this temperature range. The temperature sensitivity of the SE threshold for different samples was studied and the characteristic temperature was found to be 173 K in the temperature range of 300–700 K for one of the samples studied. We suggest that the uniq...

It has long been accepted that interannual fluctuations in sea surface temperature (SST) in the Atlantic are associated with fluctuations in seasonal Atlantic basin tropical cyclone frequency. To isolate the physical mechanism responsible for this relationship, a singular value decomposition (SVD) is used to establish the dominant covarying modes of tropospheric wind shear and SST as well as horizontal SST gradients. The dominant SVD mode of covarying vertical shear and SST gradients, which comprises equatorially confined near-zonal vertical wind shear fluctuations across the Atlantic basin, is highly correlated with both equatorial eastern Pacific SST anomalies (associated with El Nino) and West African Sahel rainfall. While this mode is strongly related to tropical storm, hurricanes, and major hurricane frequency in the Atlantic, it is not associated with any appreciable Atlantic SST signal. By contrast, the second SVD mode of covarying vertical shear and horizontal SST gradient variability, wh...

Intrinsic excitonic transitions in GaN have been studied using a variety of spectroscopic measurements. Sharp spectral structures associated with intrinsic free excitons could be observed in photoluminescence, reflection, and absorption spectra. The energy positions of excitonic transitions in GaN epitaxial layers were found to be influenced by the residual strain resulting from lattice-parameter and thermal-expansion mismatches between the epilayers and the substrates. The values of the four principal deformation potentials of wurtzite GaN were derived by using the strain tensor components determined by x-ray measurements. The observation of spectral features involving the emission of LO phonons in absorption and photoluminescence excitation spectra at energies above exciton resonances indicate that a phonon-assisted indirect excitation process, which simultaneously generates a free exciton and a LO phonon, is a very significant and efficient process in GaN. The lifetime of the free excitons is found to be longer than the relaxation time of LO-phonon emission but much shorter than that of acoustic-phonon emission.

In 2013, the vast majority of the monitored climate variables reported here maintained trends established in recent decades. ENSO was in a neutral state during the entire year, remaining mostly on the cool side of neutral with modest impacts on regional weather patterns around the world. This follows several years dominated by the effects of either La Niña or El Niño events. According to several independent analyses, 2013 was again among the 10 warmest years on record at the global scale, both at the Earths surface and through the troposphere. Some regions in the Southern Hemisphere had record or near-record high temperatures for the year. Australia observed its hottest year on record, while Argentina and New Zealand reported their second and third hottest years, respectively. In Antarctica, Amundsen-Scott South Pole Station reported its highest annual temperature since records began in 1957. At the opposite pole, the Arctic observed its seventh warmest year since records began in the early 20th century. At 20-m depth, record high temperatures were measured at some permafrost stations on the North Slope of Alaska and in the Brooks Range. In the Northern Hemisphere extratropics, anomalous meridional atmospheric circulation occurred throughout much of the year, leading to marked regional extremes of both temperature and precipitation. Cold temperature anomalies during winter across Eurasia were followed by warm spring temperature anomalies, which were linked to a new record low Eurasian snow cover extent in May. Minimum sea ice extent in the Arctic was the sixth lowest since satellite observations began in 1979. Including 2013, all seven lowest extents on record have occurred in the past seven years. Antarctica, on the other hand, had above-average sea ice extent throughout 2013, with 116 days of new daily high extent records, including a new daily maximum sea ice area of 19.57 million km2 reached on 1 October. ENSO-neutral conditions in the eastern central Pacific Ocean and a negative Pacific decadal oscillation pattern in the North Pacific had the largest impacts on the global sea surface temperature in 2013. The North Pacific reached a historic high temperature in 2013 and on balance the globally-averaged sea surface temperature was among the 10 highest on record. Overall, the salt content in nearsurface ocean waters increased while in intermediate waters it decreased. Global mean sea level continued to rise during 2013, on pace with a trend of 3.2 mm yr-1 over the past two decades. A portion of this trend (0.5 mm yr-1) has been attributed to natural variability associated with the Pacific decadal oscillation as well as to ongoing contributions from the melting of glaciers and ice sheets and ocean warming. Global tropical cyclone frequency during 2013 was slightly above average with a total of 94 storms, although the North Atlantic Basin had its quietest hurricane season since 1994. In the Western North Pacific Basin, Super Typhoon Haiyan, the deadliest tropical cyclone of 2013, had 1-minute sustained winds estimated to be 170 kt (87.5 m s-1) on 7 November, the highest wind speed ever assigned to a tropical cyclone. High storm surge was also associated with Haiyan as it made landfall over the central Philippines, an area where sea level is currently at historic highs, increasing by 200 mm since 1970. In the atmosphere, carbon dioxide, methane, and nitrous oxide all continued to increase in 2013. As in previous years, each of these major greenhouse gases once again reached historic high concentrations. In the Arctic, carbon dioxide and methane increased at the same rate as the global increase. These increases are likely due to export from lower latitudes rather than a consequence of increases in Arctic sources, such as thawing permafrost. At Mauna Loa, Hawaii, for the first time since measurements began in 1958, the daily average mixing ratio of carbon dioxide exceeded 400 ppm on 9 May. The state of these variables, along with dozens of others, and the 2013 climate conditions of regions around the world are discussed in further detail in this 24th edition of the State of the Climate series. © 2014, American Meteorological Society. All rights reserved.

We present the results of an experimental study on the binding energy for intrinsic free excitons in wurtzite GaN. High-quality single-crystal GaN films grown by metalorganic chemical vapor deposition were used in this study. Various excitonic transitions in GaN were studied using reflectance measurements. The observation of a series of spectral features associated with the transitions involving the ground and excited exciton states allows us to make a straightforward estimate of exciton binding energy using the hydrogenic model. Our results yield a binding energy ${\mathit{E}}_{\mathit{b}}$=0.021\ifmmode\pm\else\textpm\fi{}0.001 eV for the A and B excitons, and 0.023\ifmmode\pm\else\textpm\fi{}0.001 eV for the C exciton in wurtzite GaN within the framework of the effective mass approximation. \textcopyright{} 1996 The American Physical Society.

Physical mechanisms responsible for the contemporaneous association, shown in earlier studies, of North Atlantic basin major hurricane (MH) activity with western Sahelian monsoon rainfall and an equatorial eastern Pacific sea surface temperature index of El Nino are examined, using correlations with 200- and 700-mb level wind data for the period 1968–92. The use of partial correlations isolates some of the relationships associated with the various parameters. The results support previous suggestions that the upper- and lower-level winds over the region in the basin between ∼10° and 20°N where most MHs begin developing are critical determinants of the MH activity in each hurricane season. In particular, interannual fluctuations in the winds that produce changes in the magnitude of vertical shear are one of the most important factors, with reduced shear being associated with increased activity and stronger shear with decreased activity. The results show that most of these critical wind fluctuations...

We present the results of optical studies on the properties of GaN grown by low‐pressure metalorganic chemical‐vapor deposition, with emphasis on the issues vital to device applications such as stimulated emission and laser action as well as carrier relaxation dynamics. By optical pumping, stimulated emission and lasing were investigated over a wide temperature range up to 420 K. Using a picosecond streak camera, the free and bound exciton emission decay times were examined. In addition, the effects of temperature and pressure on the optical interband transitions and the transitions associated with impurity/defect states were studied using a variety of spectroscopic methods, including photoluminescence and photoreflectance. The fundamental band gap of GaN was mapped out as a function of temperature using the empirical Varshni relation. The pressure coefficient of the gap was determined using diamond‐anvil pressure‐cell technique. The hydrostatic deformation potential for the direct Γ band gap was also derived from the experimental results.

Objective—To determine the refractive states of eyes in domestic cats and to evaluate correlations between refractive error and age, breed, and axial globe measurements. Animals—98 healthy ophthalmologically normal domestic cats. Procedures—The refractive state of 196 eyes (2 eyes/cat) was determined by use of streak retinoscopy. Cats were considered ametropic when the mean refractive state was ≥ ± 0.5 diopter (D). Amplitude-mode ultrasonography was used to determine axial globe length, anterior chamber length, and vitreous chamber depth. Results—Mean ± SD refractive state of all eyes was −0.78 ± 1.37 D. Mean refractive error of cats changed significantly as a function of age. Mean refractive state of kittens (≤ 4 months old) was −2.45 ± 1.57 D, and mean refractive state of adult cats (> 1 year old) was −0.39 ± 0.85 D. Mean axial globe length, anterior chamber length, and vitreous chamber depth were 19.75 ± 1.59 mm, 4.66 ± 0.86 mm, and 7.92 ± 0.86 mm, respectively. Conclusions and Clinical Relevance—Correlations were detected between age and breed and between age and refractive states of feline eyes. Mean refractive error changed significantly as a function of age, and kittens had greater negative refractive error than did adult cats. Domestic shorthair cats were significantly more likely to be myopic than were domestic mediumhair or domestic longhair cats. Domestic cats should be included in the animals in which myopia can be detected at a young age, with a likelihood of progression to emmetropia as cats mature.

Winds at low (near-surface) and 200-mb levels from National Hurricane Center objective analyses are used to elucidate the structure and dynamics of the tropical and subtropical intraseasonal oscillations for the North Atlantic/northeast Pacific regions, including over the continents, for the years 1980–1989. The intraseasonal oscillations are broken into three bands, with long (50–85 day), intermediate (30–55 day), and short (13–29 day) periods. Winter and summer seasons are analyzed separately. A complex empirical orthogonal function technique is used to derive the dominant modes of intraseasonal variability over the region, including their propagation characteristics. Statistically distinct modes of variability are found only during the winter and only for the long-period and short-period bands. The dominant mode of coupled 200-mb low-level long-period variability during winter has a dipole structure. It has a substantial equivalent barotropic component in the subtropics, as well as a baroclini...

We present results of pressure-dependent photoluminescence (PL) studies of single-crystal AlxGa1−xN epitaxial films grown on sapphire substrates by metalorganic chemical vapor deposition. PL measurements were performed under hydrostatic pressure using the diamond-anvil-cell technique. PL spectra taken from the AlxGa1−xN epitaxial films are dominated by strong near-band-edge luminescence emissions. The emission lines were found to shift linearly towards higher energy with increasing pressure. By examining the pressure dependence of the spectral features, the pressure coefficients for the PL emissions associated with the direct Γ band gap of AlxGa1−xN were determined. Our results yield a pressure coefficient of 4.0×10−3 eV/kbar for Al0.05Ga0.95N and 3.6×10−3 eV/kbar for Al0.35Ga0.65N.

The interband optical transitions in single-crystal GaN films grown by metal organic chemical vapor deposition have been studied at 10 K and room temperature using nondegenerate nanosecond optical pump-probe techniques. At low temperatures, strong, well-resolved features are seen in the absorption and reflection spectra corresponding to the 1s A and B exciton transitions. These features broaden and decrease in intensity due to the presence of a high density of photoexcited free carriers and are completely absent in the absorption and reflection spectra as the excitation density, Iexc, approaches 3 MW/cm2, resulting in induced transparency in transmission measurements. The absorption spectra also show induced absorption below the band gap as Iexc is increased. Both the observed induced transparency and induced absorption were found to be extremely large, exceeding 4×104 cm−1 as the pump density approaches 3 MW/cm2 at 10 K.

We have investigated the spectral response of front-surface-illuminated GaN and AlGaN/GaN p-i-n ultraviolet photodetectors prepared by reactive molecular beam epitaxy on sapphire substrates. GaN homojunction p-i-n photodiodes exhibited a peaked response near the band edge. This enhanced response was absent in the AlGaN/GaN heterojunction p-i-n detectors. We analyzed the effect of p-layer thickness of the GaN p-i-n diodes on the magnitude of the peak photoresponse. The AlGaN/GaN photodiodes had a maximum zero-bias responsivity of 0.12 A/W at 364 nm, which decreased by more than 3 orders of magnitude for wavelengths longer than 390 nm. A reverse bias of −10 V raised the responsivity to 0.15 A/W without any significant increase in noise. The root-mean-square noise current in a 1 Hz bandwidth is ∼1.0 pA, corresponding to a noise-equivalent-power of ∼8.3 pW. We measured extremely fast decay times of 12 ns for the AlGaN/GaN and 29 ns for the GaN photodiodes.

Optical absorption measurements were performed on a series of thin GaN epilayers. Sharp spectral features were observed due to the 1s A and B exciton transitions. Using polarization dependent absorption, the C exciton transition was identified. A broad absorption feature was observed at ∼3.6 eV, which is attributed to indirect exciton-phonon absorption. The excitonic structure was found to persist well above room temperature. A fit to the Varshni formula yielded a temperature dependence of E(T)=E(T=0)−11.8×10−4T2(1414+T) eV for the A and B excitons. The exciton absorption linewidth was studied as a function of temperature, indicating that GaN exhibits very large exciton-phonon coupling.

Time‐resolved photoluminescence has been employed to study the mechanisms of band‐edge emissions in Mg‐doped p‐type GaN. Two emission lines at about 290 and 550 meV below the band gap (Eg) have been observed. Their recombination lifetimes, dependencies on excitation intensity, and decay kinetics have demonstrated that the line at 290 meV below Eg is due to the conduction band‐to‐impurity transition involving shallow Mg impurities, while the line at 550 meV below Eg is due to the conduction band‐to‐impurity transition involving doping related deep‐level centers (or complexes).