RESUMEN
The intense footwork required in flamenco dance may result in pain and injury. This study aimed to quantify the external load of the flamenco Zapateado-3 (Zap-3) footwork via triaxial accelerometry in the form of PlayerLoad (PL), comparing the difference in external loads at the fifth lumbar vertebra (L5), the seventh cervical vertebra (C7) and the dominant ankle (DA), and to explore whether the speed, position, axis and proficiency level of the flamenco dancer affected the external load. Twelve flamenco dancers, divided into professional and amateur groups, completed a 15-s Zap-3 footwork routine at different speeds. Triaxial accelerometry sensors were positioned at the DA, L5 and C7 and were utilized to calculate the total PlayerLoad (PLTOTAL), uniaxial PlayerLoad (PLUNI) and uniaxial contributions (PL%). For both PLTOTAL and PLUNI, this study identified significant effects of speed and position (p < 0.001), as well as the interaction between speed and position (p ≤ 0.001), and at the DA, values were significantly higher (p < 0.001) than those at C7 and L5. Significant single axis and group effects (p < 0.001) and effects of the interactions between the position and a single axis and the group and speed (p ≤ 0.001) were also identified for PLUNI. Medial-lateral PL% represented a larger contribution compared with anterior-posterior PL% and vertical PL% (p < 0.001). A significant interaction effect of position and PL% (p < 0.001) also existed. In conclusion, the Zap-3 footwork produced a significant external load at different positions, and it was affected by speed, axis and the proficiency level of the flamenco dancer. Although the ankle bears the most external load when dancing the flamenco, some external load caused by significant vibrations is also borne by the lumbar and cervical vertebrae.
Asunto(s)
Acelerometría , Baile , VibraciónRESUMEN
We present the case of a recurrent hyperammonaemic encephalopathy due to a portosystemic shunt that was successfully treated by embolization.
Asunto(s)
Embolización Terapéutica/métodos , Encefalopatía Hepática/diagnóstico por imagen , Encefalopatía Hepática/terapia , Hiperamonemia/diagnóstico por imagen , Hiperamonemia/terapia , Anciano , Cirugía Bariátrica/efectos adversos , Femenino , Humanos , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Enfermedad del Hígado Graso no Alcohólico/diagnóstico por imagen , Derivación Portosistémica Quirúrgica , Tomografía Computarizada por Rayos XRESUMEN
AIMS: Left atrial appendage (LAA) is the source of thrombi in up to 90% of patients with non-valvular atrial fibrillation (AF). Catheter ablation (CA) is an effective treatment for symptomatic AF and, in selected cases, LAA occlusion devices have been introduced as an alternative to oral anticoagulants (OACs). The safety and feasibility of combining CA and percutaneous LAA closure (LAAC) are unknown. METHODS AND RESULTS: Patients with symptomatic drug-refractory AF, CHADS2 score of ≥1, and CHA2DS2-VASc score ≥2 were included. Catheter ablation consisted in pulmonary vein isolation with or without roof line with radiofrequency and LAA was occluded with the Watchman or Amplatzer Cardiac Plug (ACP) devices guided by angiography and transoesophageal echocardiography. A total of 35 patients were included (71% male; 70 years). Median score was 3 on both CHA2DS2-VASc and HAS-BLED, 9% had prior stroke under OAC, and 48% had bleeding complications. Successful CA and device implantation were achieved in 97% of cases. The Watchman device was used in 29 patients and ACP in 6 patients. Periprocedural complications included three cases of cardiac tamponade. At 3 months, all patients met the criteria for successful sealing of the LAA. After a mean follow-up of 13 months (3-75), 78% of patients were free of arrhythmia recurrences and OAC was withheld in 97% of patients. CONCLUSIONS: The combination of CA and percutaneous LAAC in a single procedure is technically feasible in patients with symptomatic drug-refractory AF, high risk of stroke, and contraindications to OACs, although it is associated with a significant risk of major complications.
Asunto(s)
Apéndice Atrial/cirugía , Fibrilación Atrial/cirugía , Ablación por Catéter , Venas Pulmonares/cirugía , Dispositivo Oclusor Septal , Anciano , Anticoagulantes/uso terapéutico , Ecocardiografía Transesofágica , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
OBJECTIVES: The objectives of this study were to determine the frequency of metatarsal pain and of hyperkeratosis on the plantar forefoot in female professional flamenco dancers, and to determine whether there is a relationship between the two disorders. METHOD: Forty-four female professional flamenco dancers, with a minimum activity of 25 hrs/wk, participated in this cross-sectional study. The presence or absence of metatarsal pain while dancing was recorded, and plantar pressures were measured on a pressure platform, both barefoot and shod with the usual dance shoe. The heel height of the dance shoe was also measured. RESULTS: Of the dancers, 80.7% experienced metatarsal pain while dancing, and 84.1% presented with plantar hyperkeratosis. Plantar hyperkeratosis coincided with the presence of metatarsal pain in 67.04% of the feet studied. The maximum load point in the feet when the dancers were barefoot was located 59.5% in the rearfoot and 40.5% in the forefoot; when dancers wore their specific flamenco dancing shoes, it was located 52.4% in the rearfoot and 47.6% in the forefoot. CONCLUSIONS: Metatarsal pain and plantar hyperkeratosis in the forefoot are common foot disorders in female flamenco dancing. The incidence of the maximum load point being located in the forefoot, and the difference between the results of the tests while shod or barefoot, are both too low to support the idea that the raised heels of flamenco shoes are a major contributing factor for these injuries. Therefore, these disorders may be caused by chronic repetitive trauma suffered during the practice of footwork dancing.
Asunto(s)
Baile/fisiología , Queratodermia Palmoplantar/diagnóstico , Metatarsalgia/diagnóstico , Articulación Metatarsofalángica , Enfermedades Profesionales/diagnóstico , Soporte de Peso/fisiología , Adulto , Estudios Transversales , Femenino , Estado de Salud , Humanos , Queratodermia Palmoplantar/prevención & control , Metatarsalgia/prevención & control , Enfermedades Profesionales/prevención & control , Salud de la Mujer , Adulto JovenRESUMEN
Repatterning is a term that can be used in different fields, including genetics, molecular biology, neurology, psychology, or rehabilitation. Our aim is to identify the key concept of neuromuscular repatterning in somatic training programmes for dancers. A systematic search of eight databases was conducted using the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines. The Quality Assessment Tool for Quantitative Studies and the Oxford Levels of Evidence scales were used. The search yielded 1218 results, of which 5 met the inclusion criteria. Five studies (n = 5) were related to psychosomatic health (n = 5), two studies highlighted integration and inter-articular connectivity in movement (n = 2), four studies investigated the neurological component of alignment and efficiency in dance practice (n = 4), and two studies investigated self-confidence (n = 2). Five studies (n = 5) used imagery based on the anatomical and physiological experience of body systems as the main analytical method. Four studies (n = 4) used developmental movement through Bartenieff fundamentals as the main technique for this methodology. Developmental movement and imagery are two methodologies strongly connected to the concept of neuromuscular repatterning in somatic training programmes for dancers. The acquisition of further quantitative experimental or quasi-experimental studies is warranted to better define the level of improvement or impact of neuromuscular repatterning in dancers.
Asunto(s)
Antiinflamatorios no Esteroideos/efectos adversos , Fiebre/inducido químicamente , Mesalamina/efectos adversos , Corticoesteroides/uso terapéutico , Antibacterianos/uso terapéutico , Antiinflamatorios no Esteroideos/uso terapéutico , Enfermedad de Crohn/tratamiento farmacológico , Femenino , Fiebre/terapia , Fluidoterapia , Humanos , Mesalamina/uso terapéutico , Persona de Mediana Edad , Norepinefrina/uso terapéutico , Sacroileítis/tratamiento farmacológicoRESUMEN
BACKGROUND: The objective of this study is to analyze the factors that are associated with the adequacy of empirical antibiotic therapy and its impact in mortality in a large cohort of patients with extended-spectrum ß-lactamase (ESBL)--producing Escherichia coli and Klebsiella spp. bacteremia. METHODS: Cases of ESBL producing Enterobacteriaceae (ESBL-E) bacteremia collected from 2003 through 2008 in 19 hospitals in Spain. Statistical analysis was performed using multivariate logistic regression. RESULTS: We analyzed 387 cases ESBL-E bloodstream infections. The main sources of bacteremia were urinary tract (55.3%), biliary tract (12.7%), intra-abdominal (8.8%) and unknown origin (9.6%). Among all the 387 episodes, E. coli was isolated from blood cultures in 343 and in 45.71% the ESBL-E was multidrug resistant. Empirical antibiotic treatment was adequate in 48.8% of the cases and the in hospital mortality was 20.9%. In a multivariate analysis adequacy was a risk factor for death [adjusted OR (95% CI): 0.39 (0.31-0.97); P = 0.04], but not in patients without severe sepsis or shock. The class of antibiotic used empirically was not associated with prognosis in adequately treated patients. CONCLUSION: ESBL-E bacteremia has a relatively high mortality that is partly related with a low adequacy of empirical antibiotic treatment. In selected subgroups the relevance of the adequacy of empirical therapy is limited.
Asunto(s)
Antibacterianos/uso terapéutico , Bacteriemia/tratamiento farmacológico , Infecciones por Escherichia coli/tratamiento farmacológico , Escherichia coli/enzimología , Infecciones por Klebsiella/tratamiento farmacológico , Klebsiella/enzimología , beta-Lactamasas/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Bacteriemia/microbiología , Bacteriemia/mortalidad , Niño , Preescolar , Estudios de Cohortes , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/mortalidad , Femenino , Humanos , Lactante , Recién Nacido , Klebsiella/aislamiento & purificación , Infecciones por Klebsiella/microbiología , Infecciones por Klebsiella/mortalidad , Masculino , Persona de Mediana Edad , España , Análisis de Supervivencia , Resultado del Tratamiento , Adulto JovenAsunto(s)
Tumores Fibrosos Solitarios/diagnóstico por imagen , Neoplasias Gástricas/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Anciano , Enfermedades Asintomáticas , Humanos , Hallazgos Incidentales , Laparoscopía , Masculino , Tumores Fibrosos Solitarios/patología , Tumores Fibrosos Solitarios/cirugía , Neoplasias Gástricas/patología , Neoplasias Gástricas/cirugíaRESUMEN
BACKGROUND: The practice of flamenco dance involves great biomechanical demands, comparable with a high-performance sport. The technical movements of the footwork tap, the jumps, and the turns increase the prevalence of injuries and pathologic disorders of the foot and lower limb. Limited research has examined adaptation of the foot posture and dorsiflexion of the ankle in flamenco dancing. Therefore, the aim of this study was to evaluate whether the practice of flamenco dancing produces modifications in the ankle's dorsiflexion range of motion, Foot Posture Index, or pronation. METHODS: A cross-sectional observational study with intentional sampling was performed with 26 individuals (52 feet) in two groups: professional female flamenco dancers (n = 13) and nondancers (n = 13). The participants were assessed in a single session for ankle dorsiflexion, foot pronation (navicular drop test), and foot posture (Foot Posture Index). RESULTS: Significant differences were found between the two groups for left foot Foot Posture Index (P = .007) and right foot navicular drop test (P = .006). CONCLUSIONS: The results of this study indicate that flamenco dancing can produce modifications in the Foot Posture Index and foot pronation versus nondancers. Further research is required.
Asunto(s)
Baile , Tobillo , Estudios Transversales , Femenino , Humanos , Extremidad Inferior , PosturaRESUMEN
AIMS: Although transplantation of skeletal myoblast (SkM) in models of chronic myocardial infarction (MI) induces an improvement in cardiac function, the limited engraftment remains a major limitation. We analyse in a pre-clinical model whether the sequential transplantation of autologous SkM by percutaneous delivery was associated with increased cell engraftment and functional benefit. METHODS AND RESULTS: Chronically infarcted Goettingen minipigs (n = 20) were divided in four groups that received either media control or one, two, or three doses of SkM (mean of 329.6 x 10(6) cells per dose) at intervals of 6 weeks and were followed for a total of 7 months. At the time of sacrifice, cardiac function was significantly better in animals treated with SkM in comparison with the control group. A significantly greater increase in the DeltaLVEF was detected in animals that received three doses vs. a single dose of SkM. A correlation between the total number of transplanted cells and the improvement in LVEF and DeltaLVEF was found (P < 0.05). Skeletal myoblast transplant was associated with an increase in tissue vasculogenesis and decreased fibrosis (collagen vascular fraction) and these effects were greater in animals receiving three doses of cells. CONCLUSION: Repeated injection of SkM in a model of chronic MI is feasible and safe and induces a significant improvement in cardiac function.
Asunto(s)
Mioblastos Esqueléticos/trasplante , Infarto del Miocardio/terapia , Animales , Arritmias Cardíacas/etiología , Diferenciación Celular , Enfermedad Crónica , Fibrosis , Supervivencia de Injerto , Inmunohistoquímica , Mioblastos Esqueléticos/citología , Miocardio/patología , Neovascularización Fisiológica/fisiología , Porcinos , Porcinos Enanos , Disfunción Ventricular Izquierda/etiología , Remodelación Ventricular/fisiologíaRESUMEN
The aims of this study were to describe the sagittal integral morphotype (SIM) of classical ballet (CB) dancers, and to establish predictor factors and their cut off values for high risk of experiencing sciatica or low back pain (LBP). This retrospective cohort study was performed in 33 female professional CB dancers. Data related to anthropometric parameters, CB dance experience, sciatica or LBP history, and sagittal spine curvatures were collected. A binary logistic regression and receiver-operating characteristic analysis were performed. The main spine misalignments observed in the SIM of CB dancers were thoracic functional hyperkyphosis, hypomobile kyphosis, and hypokyphosis, and those for the lumbar curvature were hyperlordotic attitude and functional hyperkyphosis. The lumbar curvature in slump sitting and trunk forward bending positions, together with the stature, were significant predictor factors of sciatica history, while the years of dance experience was a significant predictor factor of LBP history. The cut off values analysis revealed that dancers with a stature of 161 cm or less, and those with 14 years of experience or more, have a greater probability of experiencing sciatica or LBP history, respectively.
Asunto(s)
Baile , Dolor de la Región Lumbar , Ciática , Estudios Transversales , Femenino , Humanos , Dolor de la Región Lumbar/epidemiología , Dolor de la Región Lumbar/etiología , Estudios Retrospectivos , Ciática/epidemiología , Ciática/etiologíaRESUMEN
The main purpose of this study was to identify a dancer's body alignment while performing flamenco footwork to provide a detailed description that could be used by flamenco practitioners: teachers, instructors and students of different levels of advancement. The zapateado technique performed by a professional flamenco dancer was analyzed. The biomechanical analysis was based on 30 cycles composed of six repeating sequences of strikes. Kinematic recordings were performed using a Vicon system, while the measurement of the ground reaction forces (GRF) was accomplished with a Kistler force plate. The following parameters were analyzed: the time of each foot strike, the maximal value of the vertical component of GRF normalized to body weight (BW) for subsequent footwork steps, the impulse of the GRF and the kinematics of pelvis and lower limb joints, and an exemplary waveform view of the sound of footwork strikes was shown. The average values of the vertical component of GRF ranged between 0.6 and 2.7 BW. The maximal anterior pelvic tilt was 29°, with a 6° range of motion (RoM). This mobility was accompanied by 20° hip RoM and by ~40° knee RoM throughout flexion. The conclusions provide practical information that a teacher and flamenco student should receive.
Asunto(s)
Pie , Extremidad Inferior , Fenómenos Biomecánicos , Humanos , Articulación de la Rodilla , Rango del Movimiento ArticularRESUMEN
Footwork is one of the basic features of flamenco dancing and is performed in traditional high-heeled shoes. The purpose of this study was to analyse the mechanical profile of flamenco dancing in terms of vertical ground reaction force, and knee joint kinematics of the supporting limb in footwork technique in order to understand causes which predispose injuries derived from the practice of flamenco dancing. The participant in our study was a professional female flamenco dancer (34 years, 58 kg, 1.65 m) who performed the ZAP 3 test, a sequence of single strikes of the feet performed continuously for 15 s. 3D lower extremity kinematic data were collected using a five-camera motion analysis system (Vicon; Oxford Metrics Ltd., Oxford, UK). Ground reaction forces were recorded using a Kistler force plate. Our analysis was based on 30 cycles of each lower limb consisting of 177 footwork steps. The vertical component of the ground reaction force did not reveal any significant differences between the left and the right limb. The most dynamic strike was provided by the heel (twice the participant's body weight). The mean angular displacement of the supporting limb's knee was ~27°. Results reveal that these impacts could make the knee joint more prone to injuries.
RESUMEN
Background: Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. It is exposed a clinical case of jejunal GIST from a second-level hospital in Mexico. Clinical case: Female patient of 76 years, with history of tobacco use (two cigarettes per day for 25 years), that is referred to General Surgery due to a four month evolution of symptoms, characterized by abdominal pain, hyporexia and urinary symptomatology. Physical examination revealed a non-pulsatile, solid, non-mobile, non-painful mass in the hypogastrium and right iliac fossa of approximately 15 cm in length. Ovarian tumor was ruled out, since CEA and CA-125 tumor markers were negative. Abdominopelvic ultrasound was performed and reported a solid tumor with cystic spaces inside. CT reported a solid tumor of 9.5 x 2.5 x 8.3 cm, with defined edges, multilobed, presence of some calcifications in its wall that did not show enhancement with the use of contrast media. Patient underwent exploratory laparotomy and it was found a jejunal tumor, 210 cm from the ligament of Treitz. Immunohistochemistry reported positivity to KIT and DOG1, confirming the diagnosis of GIST. Conclusion: GISTs are uncommon entities. Their clinical presentation is insidious and the preoperative diagnosis is complex due to the need for biopsy. The treatment is surgery, but tyrosine kinase inhibitors should be administered. Even in patients with response to treatment, follow-up is mandatory due to the risk of recurrence.
Introducción: los tumores del estroma gastrointestinal (GIST) son los tumores mesenquimatosos más comunes del tracto gastrointestinal. Se expone un caso clínico de GIST en yeyuno que se presentó en un hospital de segundo nivel en México. Caso clínico: femenino de 76 años, con antecedente de tabaquismo (dos cigarros diarios durante 25 años), referida a Cirugía General por cuadro de cuatro meses de evolución (dolor abdominal tipo cólico en hipogastrio, hiporexia y sintomatología urinaria). A la exploración física, se le detectó tumor no pulsátil, sólido, no móvil, no doloroso, adherido a planos profundos en hipogastrio y fosa ilíaca derecha de aprox. 15 cm de longitud. Se descartó tumor ovárico al resultar negativos los marcadores tumorales ACE y CA-125. Se realizó ultrasonido abdominopélvico que reportó imagen de tumoración sólida con zonas quísticas en su interior. La TC reportó tumoración sólida, de bordes definidos, multilobulada con algunas calcificaciones milimétricas en su pared de 9.5 x 2.5 x 8.3 cm y sin realce al administrar medio de contraste. La paciente se sometió a laparotomía exploradora y se encontró tumoración adherida a yeyuno a 210 cm del ligamento de Treitz. El tumor fue positivo a KIT y DOG1, lo que confirmó el diagnóstico de GIST de patrón fusiforme. Conclusión: los GIST son poco frecuentes. Su presentación clínica es insidiosa y el diagnóstico preoperatorio es complejo debido a la toma de biopsia. El tratamiento continúa siendo la cirugía, pero se deben administrar inhibidores de la tirosina cinasa. Incluso en pacientes con respuesta favorable al tratamiento, se recomienda seguimiento por riesgo de recidiva.
Asunto(s)
Tumores del Estroma Gastrointestinal , Anciano , Antineoplásicos/uso terapéutico , Femenino , Tumores del Estroma Gastrointestinal/diagnóstico , Tumores del Estroma Gastrointestinal/patología , Tumores del Estroma Gastrointestinal/cirugía , Humanos , Inmunohistoquímica , México , Recurrencia Local de Neoplasia , Proto-Oncogenes MasRESUMEN
Cardiac changes may occasionally occur during vagus nerve stimulation (VNS) used in epileptic patients. As they can be potentially life-threatening, it is important to detect them, and this is why an intraoperative test is performed during the implantation. Few cases of asystole during this test have been described. Only one patient with late-onset bradyarrythmia caused by VNS has been reported. This patient had been implanted 2 years and 4 months before the episode. We present another case of late asystole in a patient whose VNS had been implanted 9 years before the arrhythmia onset. In our patient, each run of stimulation produced bradyarrhythmias and very often severe asystolia due to atrium-ventricular block.
Asunto(s)
Paro Cardíaco/etiología , Estimulación del Nervio Vago/efectos adversos , Electrocardiografía/métodos , Electroencefalografía , Epilepsia/terapia , Femenino , Humanos , Persona de Mediana EdadAsunto(s)
Antibacterianos/uso terapéutico , Ceftriaxona/uso terapéutico , Endocarditis Bacteriana/tratamiento farmacológico , Enfermedades de las Válvulas Cardíacas/tratamiento farmacológico , Enfermedades de las Válvulas Cardíacas/microbiología , Válvula Mitral , Infecciones por Salmonella/tratamiento farmacológico , Salmonella enteritidis , Anciano de 80 o más Años , Humanos , Masculino , Inducción de RemisiónAsunto(s)
Insuficiencia Respiratoria , Telangiectasia Hemorrágica Hereditaria , Humanos , Telangiectasia Hemorrágica Hereditaria/complicaciones , Telangiectasia Hemorrágica Hereditaria/diagnóstico , Telangiectasia Hemorrágica Hereditaria/genética , Mutación , Insuficiencia Respiratoria/etiología , Endoglina/genéticaRESUMEN
INTRODUCTION AND OBJECTIVES: We describe the results for Spain of the Second European Cardiac Resynchronization Therapy Survey (CRT-Survey II) and compare them with those of the other participating countries. METHODS: We included patients undergoing CRT device implantation between October 2015 and December 2016 in 36 participating Spanish centers. We registered the patients' baseline characteristics, implant procedure data, and short-term follow-up information until hospital discharge. RESULTS: Implant success was achieved in 95.9%. The median [interquartile range] annual implantation rate by center was significantly lower in Spain than in the other participating countries: 30 implants/y [21-50] vs 55 implants/y [33-100]; P=.00003. In Spanish centers, there was a lower proportion of patients ≥ 75 years (27.9% vs 32.4%; P=.0071), a higher proportion in New York Heart Association functional class II (46.9% vs 36.9%; P <.00001), and a higher percentage with electrocardiographic criteria of left bundle branch block (82.9% vs 74.6%; P <.00001). The mean length of hospital stay was significantly lower in Spanish centers (5.8±8.5 days vs 6.4±11.6; P <.00001). Spanish patients were more likely to receive a quadripolar LV lead (74% vs 56%; P <.00001) and to be followed up by remote monitoring (55.8% vs 27.7%; P <.00001). CONCLUSIONS: The CRT-Survey II shows that, compared with other participating countries, fewer patients in Spain aged ≥ 75 years received a CRT device, while more patients were in New York Heart Association functional class II and had left bundle branch block. In addition, the length of hospital stay was shorter, and there was greater use of quadripolar LV leads and remote CRT monitoring.
Asunto(s)
Arritmias Cardíacas/terapia , Terapia de Resincronización Cardíaca/estadística & datos numéricos , Encuestas y Cuestionarios , Anciano , Arritmias Cardíacas/epidemiología , Electrocardiografía , Europa (Continente)/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Morbilidad/tendencias , Estudios Retrospectivos , España/epidemiologíaRESUMEN
The mouse macrophage-like cell line RAW264.7, the most commonly used mouse macrophage cell line in medical research, was originally reported to be free of replication-competent murine leukemia virus (MuLV) despite its origin in a tumor induced by Abelson MuLV containing Moloney MuLV as helper virus. As currently available, however, we find that it produces significant levels of ecotropic MuLV with the biologic features of the Moloney isolate and also MuLV of the polytropic or MCF class. Newborn mice developed lymphoma following inoculation with the MuLV mixture expressed by these cells. These findings should be considered in interpretation of increasingly widespread use of these cells for propagation of other viruses, studies of biological responses to virus infection and use in RNA interference and cell signalling studies.