Spelling Proficiency of Children with a Resolved Phonological Speech Sound Disorder Treated with an Integrated Approach-A Long-Term Follow-Up Randomized Controlled Trial.

Phonological developmental speech sound disorders (pDSSD) in childhood are often associated with later difficulties in literacy acquisition. The present study is a follow-up of the randomized controlled trial (RCT) on the effectiveness of PhonoSens, a treatment for pDSSD that focuses on improving auditory self-monitoring skills and categorial perception of phoneme contrasts, which could have a positive impact on later spelling development. Our study examines the spelling abilities of 26 German-speaking children (15 girls, 11 boys; mean age 10.1 years, range 9.3-11.2 years) 3-6 years after their successful completion of the PhonoSens treatment. Spelling assessment revealed that only 3 out of 26 participants developed a spelling disorder. In the overall population of fourth-graders, one in five children showed a spelling deficit; in another study of elementary school children, with resolved pDSSD, 18 of 32 children had a spelling deficit. Thus, the applied pDSSD treatment method appears to be associated with positive spelling development. Multiple regression analysis revealed that among the potentially predictive factors for German-speaking children with resolved pDSSD to develop later spelling difficulties, parental educational level and family risk for developmental language disorder (DLD) had an impact on children's spelling abilities; gender and the child's phonological memory had not.

Newborn Hearing Screening Benefits Children, but Global Disparities Persist.

There is substantial evidence that newborn hearing screening (NHS) reduces the negative sequelae of permanent childhood hearing loss (PCHL) if performed in programs that aim to screen all newborns in a region or nation (often referred to as Universal Newborn Hearing Screening or UNHS). The World Health Organization (WHO) has called in two resolutions for the implementation of such programs and for the collection of large-scale data. To assess the global status of NHS programs we surveyed individuals potentially involved with newborn and infant hearing screening (NIHS) in 196 countries/territories (in the following text referred to as countries). Replies were returned from 158 countries. The results indicated that 38% of the world's newborns and infants had no or minimal hearing screening and 33% screened at least 85% of the babies (hereafter referred to as UNHS). Hearing screening programs varied considerably in quality, data acquisition, and accessibility of services for children with PCHL. In this article, we summarize the main results of the survey in the context of several recent WHO publications, particularly the World Report on Hearing, which defined advances in the implementation of NHS programs in the Member States as one of three key indicators of worldwide progress in ear and hearing care (EHC).

The Effectiveness of an Integrated Treatment for Functional Speech Sound Disorders-A Randomized Controlled Trial.

BACKGROUND: The treatment of functional speech sound disorders (SSDs) in children is often lengthy, ill-defined, and without satisfactory evidence of success; effectiveness studies on SSDs are rare. This randomized controlled trial evaluates the effectiveness of the integrated SSD treatment program PhonoSens, which focuses on integrating phonological and phonetic processing according to the Integrated Psycholinguistic Model of Speech Processing (IPMSP). METHODS: Thirty-two German-speaking children aged from 3.5 to 5.5 years (median 4.6) with functional SSD were randomly assigned to a treatment or a wait-list control group with 16 children each. All children in the treatment group and, after an average waiting period of 6 months, 12 children in the control group underwent PhonoSens treatment. RESULTS: The treatment group showed more percent correct consonants (PCC) and a greater reduction in phonological processes after 15 therapy sessions than the wait-list control group, both with large effect sizes (Cohen's d = 0.89 and 1.04). All 28 children treated achieved normal phonological abilities: 21 before entering school and 7 during first grade. The average number of treatment sessions was 28; the average treatment duration was 11.5 months. CONCLUSION: IPMSP-aligned therapy is effective in the treatment of SSD and is well adaptable for languages other than German.

Speech restructuring group treatment for 6-to-9-year-old children who stutter: A therapeutic trial.

For children who stutter (CWS), there is good evidence of the benefits of treatment for pre-school age, but an evidence gap for elementary school age. Here we report on the effectiveness of a fluency shaping treatment for 6- to 9-year-old children. The main treatment component is the reinforcement of soft voice onsets. An intensive in-patient group treatment phase lasts 6 days, followed by a 6-month maintenance phase with 3 in-patient weekend group refresher courses. Child and a parent participate together in various treatment activities. In this controlled intervention study (waitlist control, intention-to-treat design) assessments were performed before treatment (T1), 4 weeks after the intensive phase (T2), at the end of the maintenance phase (T3), and 1 year later (T4). Participants were 119 children (108 boys, 11 girls, age 5.5­10.4 years). Control conditions included a subgroup with delayed treatment (N=25) as well as the assessment of complexity of utterances, inter-rater reliability, and speech naturalness. From before treatment to 1-year follow-up, percent stuttered syllables and OASES-S (Overall Assessment of the Speaker's Experience with Stuttering - School-age) scores decreased with large effect size. Speech naturalness improved during this period but did not reach the level of non-stuttering children. Complexity of utterances increased during the intensive phase, but only temporarily. Twenty children (16.8 %, including dropouts) showed no demonstrable treatment benefit. Fluency shaping treatment can be effectively applied to young school children. It is assumed that parental support, group therapy, intensive treatment, and regular exercises at home are essential.

Gender differences in attachment from an evolutionary perspective: what is Good for the goose may not be good for the gander.

Human gender differences tend to be largest in behaviors of high reproductive relevance, that is, sexual and parenting behavior. Such differences show up best in biologically meaningful configurations of specific behaviors rather than in coarse categories. Paternal involvement is thus expressed in aspects and optima which differ from those of maternal involvement. A case in point is sensitivity in its effect on secure attachment, with paternal behavior to be measured by a yardstick different from maternal behavior. Secure father-child attachment may be fostered by optimal levels of paternal activation/stimulation which are different from maternal optima. Paternal action preferences lead to preferences for rough play, which may be especially relevant to the socialization of male offspring. Moreover, fathers-unlike mothers-may perceive their paternal effort as mating effort. The study of father-child attachment-and especially its differences from mother-child attachment-can benefit from considering evolved sex differences in parental behavior.

"Spontaneous" late recovery from stuttering: Dimensions of reported techniques and causal attributions.

PURPOSE: (1) To survey the employed techniques and the reasons/occasions which adults who had recovered from stuttering after age 11 without previous treatment reported as causal to overcome stuttering, (2) to investigate whether the techniques and causal attributions can be reduced to coherent (inherently consistent) dimensions, and (3) whether these dimensions reflect common therapy components. METHODS: 124 recovered persons from 8 countries responded by SurveyMonkey or paper-and-pencil to rating scale questions about 49 possible techniques and 15 causal attributions. RESULTS: A Principal Component Analysis of 110 questionnaires identified 6 components (dimensions) for self-assisted techniques (Speech Restructuring; Relaxed/Monitored Speech; Elocution; Stage Performance; Sought Speech Demands; Reassurance; 63.7% variance explained), and 3 components of perceived causal attributions of recovery (Life Change, Attitude Change, Social Support; 58.0% variance explained). DISCUSSION: Two components for self-assisted techniques (Speech Restructuring; Elocution) reflect treatment methods. Another component (Relaxed/Monitored Speech) consists mainly of items that reflect a common, non-professional understanding of effective management of stuttering. The components of the various perceived reasons for recovery reflect differing implicit theories of causes for recovery from stuttering. These theories are considered susceptible to various biases. This identification of components of reported techniques and of causal attributions is novel compared to previous studies who just list techniques and attributions. CONCLUSION: The identified dimensions of self-assisted techniques and causal attributions to reduce stuttering as extracted from self-reports of a large, international sample of recovered formerly stuttering adults may guide the application of behavioral stuttering therapies.

Stuttering treatment and brain research in adults: A still unfolding relationship.

PURPOSE: Brain imaging and brain stimulation procedures have now been used for more than two decades to investigate the neural systems that contribute to the occurrence of stuttering in adults, and to identify processes that might enhance recovery from stuttering. The purpose of this paper is to review the extent to which these dual lines of research with adults who stutter have intersected and whether they are contributing towards the alleviation of this impairment. METHOD: Several areas of research are reviewed in order to determine whether research on the neurology of stuttering is showing any potential for advancing the treatment of this communication disorder: (a) attempts to discover the neurology of stuttering, (b) neural changes associated with treated recovery, and (c) direct neural intervention. RESULTS AND CONCLUSIONS: Although much has been learned about the neural underpinnings of stuttering, little research in any of the reviewed areas has thus far contributed to the advancement of stuttering treatment. Much of the research on the neurology of stuttering that does have therapy potential has been largely driven by a speech-motor model that is designed to account for the efficacy of fluency-inducing strategies and strategies that have been shown to yield therapy benefits. Investigations on methods that will induce neuroplasticity are overdue. Strategies profitable with other disorders have only occasionally been employed. However, there are signs that investigations on the neurology of adults who have recovered from stuttering are slowly being recognized for their potential in this regard.

Assisted and unassisted recession of functional anomalies associated with dysprosody in adults who stutter.

PURPOSE: Speech in persons who stutter (PWS) is associated with disturbed prosody (speech melody and intonation), which may impact communication. The neural correlates of PWS' altered prosody during speaking are not known, neither is how a speech-restructuring therapy affects prosody at both a behavioral and a cerebral level. METHODS: In this fMRI study, we explored group differences in brain activation associated with the production of different kinds of prosody in 13 male adults who stutter (AWS) before, directly after, and at least 1 year after an effective intensive fluency-shaping treatment, in 13 typically fluent-speaking control participants (CP), and in 13 males who had spontaneously recovered from stuttering during adulthood (RAWS), while sentences were read aloud with 'neutral', instructed emotional (happy), and linguistically driven (questioning) prosody. These activations were related to speech production acoustics. RESULTS: During pre-treatment prosody generation, the pars orbitalis of the left inferior frontal gyrus and the left anterior insula were activated less in AWS than in CP. The degree of hypo-activation correlated with acoustic measures of dysprosody. Paralleling the near-normalization of free speech melody following fluency-shaping therapy, AWS normalized the inferior frontal hypo-activation, sooner after treatment for generating emotional than linguistic prosody. Unassisted recovery was associated with an additional recruitment of cerebellar resources. CONCLUSIONS: Fluency shaping therapy may restructure prosody, which approaches that of typically fluent-speaking people. Such a process may benefit from additional training of instructed emotional and linguistic prosody by inducing plasticity in the inferior frontal region which has developed abnormally during childhood in PWS.

Altered morphology of the nucleus accumbens in persistent developmental stuttering.

PURPOSE: Neuroimaging studies in persistent developmental stuttering repeatedly report altered basal ganglia functions. Together with thalamus and cerebellum, these structures mediate sensorimotor functions and thus represent a plausible link between stuttering and neuroanatomy. However, stuttering is a complex, multifactorial disorder. Besides sensorimotor functions, emotional and social-motivational factors constitute major aspects of the disorder. Here, we investigated cortical and subcortical gray matter regions to study whether persistent developmental stuttering is also linked to alterations of limbic structures. METHODS: The study included 33 right-handed participants who stutter and 34 right-handed control participants matched for sex, age, and education. Structural images were acquired using magnetic resonance imaging to estimate volumetric characteristics of the nucleus accumbens, hippocampus, amygdala, pallidum, putamen, caudate nucleus, and thalamus. RESULTS: Volumetric comparisons and vertex-based shape comparisons revealed structural differences. The right nucleus accumbens was larger in participants who stutter compared to controls. CONCLUSION: Recent theories of basal ganglia functions suggest that the nucleus accumbens is a motivation-to-movement interface. A speaker intends to reach communicative goals, but stuttering can derail these efforts. It is therefore highly plausible to find alterations in the motivation-to-movement interface in stuttering. While behavioral studies of stuttering sought to find links between the limbic and sensorimotor system, we provide the first neuroimaging evidence of alterations in the limbic system. Thus, our findings might initialize a unified neurobiological framework of persistent developmental stuttering that integrates sensorimotor and social-motivational neuroanatomical circuitries.

The Pathogenesis, Assessment and Treatment of Speech Fluency Disorders.

BACKGROUND: Approximately 1% of children and adolescents, 0.2% of women, and 0.8% of men suffer from stuttering, and lesser numbers from cluttering. Persistent speech fluency disorders often cause lifelong problems in communication and social participation. METHODS: In an interdisciplinary, evidence and consensus based clinical practice guideline, the current understanding of the nature, identification, diagnosis, and treatment of stuttering and cluttering was summarized. A systematic review of the literature was carried out to assess the efficacy and effectiveness of treatments for stuttering. Evidence is lacking on the etiology, pathogenesis, evaluation, and treatment of cluttering. RESULTS: In view of the fact that common (developmental, idiopathic) stuttering is associated with structural and functional changes of the brain, the guideline recommends that it should be called "originary neurogenic non-syndromic stuttering." Heritability estimates for this disorder range from 70% to over 80%. For preschool children, the Lidcombe therapy has the best evidence of efficacy (Cohen's d = 0.72-1.00). There is also strong evidence for an indirect treatment approach. For children aged 6 to 12, there is no solid evidence for the efficacy of any treatment. For adolescents and adults, there is good evidence with high effect sizes (Cohen's d = 0.75-1.63) for speech restructuring methods such as fluency shaping; weak evidence with intermediate effect sizes for stuttering modification (Cohen's d = 0.56-0.65); and weak evidence for combined speech restructuring and stuttering modification. The evidence does not support the efficacy of pharmacotherapy, rhythmic speaking, or breathing regulation as the sole or main form of treatment, or that of hypnosis or eclectic, unspecified stuttering therapies. CONCLUSION: Stuttering is often treated in Germany with therapies for which there is inadequate evidence, and the initiation of treatment is often unnecessarily delayed. The guideline presents treatment methods whose efficacy is supported by the current evidence.

The effectiveness of stuttering treatments in Germany.

PURPOSE: Persons who stutter (PWS) should be referred to the most effective treatments available, locally or regionally. A prospective comparison of the effects of the most common stuttering treatments in Germany is not available. Therefore, a retrospective evaluation by clients of stuttering treatments was carried out. METHOD: The five most common German stuttering treatments (231 single treatment cases) were rated as to their perceived effectiveness, using a structured questionnaire, by 88 PWS recruited through various sources. The participants had received between 1 and 7 treatments for stuttering. RESULTS: Two stuttering treatments (stuttering modification, fluency shaping) showed favorable and three treatments (breathing therapy, hypnosis, unspecified logopedic treatment) showed unsatisfactory effectiveness ratings. The effectiveness ratings of stuttering modification and fluency shaping did not differ significantly. The three other treatments were equally ineffective. The differences between the effective and ineffective treatments were of large effect sizes. The typical therapy biography begins in childhood with an unspecified logopedic treatment administered extensively in single and individual sessions. Available comparisons showed intensive or interval treatments to be superior to extensive treatments, and group treatments to be superior to single client treatments. CONCLUSION: The stuttering treatment most often prescribed in Germany, namely a weekly session of individual treatment by a speech-language pathologist, usually with an assorted package of mostly unknown components, is of limited effectiveness. Better effectiveness can be expected from fluency shaping or stuttering modification approaches, preferably with an intensive time schedule and with group sessions. EDUCATIONAL OBJECTIVES: Readers will be able to: (a) discuss the five most prevalent stuttering treatments in Germany; (b) summarize the effectiveness of these treatments; and (c) describe structural treatment components that seem to be preferable across different kinds of treatments.

Regioselective synthesis of 7,8-dihydroimidazo[5,1-c][1,2,4]triazine-3,6(2H,4H)-dione derivatives: A new drug-like heterocyclic scaffold.

Dihydroimidazo[5,1-c][1,2,4]triazine-3,6(2H,4H)-dione derivatives were prepared by successive N3- and N1-alkylation of hydantoins, followed by regioselective thionation and subsequent cyclization under mild conditions. In a final alkylation step a further substituent may be introduced. The synthetic strategy allows broad structural variation of this new drug-like heterobicyclic scaffold. In addition to extensive NMR and MS analyses, the structure of one derivative was confirmed by X-ray crystallography.

Speech audiometry in quiet with the Oldenburg Sentence Test for Children.

OBJECTIVE: To assess speech perception in children, speech audiometric sentence tests are generally better suited than single word tests because of their steeper discrimination function and thus higher sensitivity. A disadvantage of older German single word speech audiometric tests for children is their inapplicability in quiet and in noise. Moreover, their discrimination functions are shallower than those of optimized sentence tests, particularly in noise. The Oldenburg sentence test for children (Oldenburger Kinder-Satztest; OlKiSa) has already been shown to test reliably the speech perception in noise in normal-hearing children. Testing hearing-impaired children in noise, however, may be difficult. Therefore, quality criteria and norms for testing in quiet are also needed. STUDY SAMPLE: The OlKiSa in quiet was validated with 224 normal-hearing children between ages 4 to 10 years. RESULTS: The discrimination functions are steeper (6.4 to 10.7 %/dB) than those of the commonly used German single word tests. Age-specific standards for 50% speech perception in quiet (speech reception threshold, SRT) are provided. CONCLUSIONS: The OlKiSa is a valid audiometric test to quantify speech perception in quiet in children from age 4.

A documentation system to save time and ensure proper application of the fiberoptic endoscopic evaluation of swallowing (FEES®).

A properly performed fiberoptic endoscopic evaluation of swallowing (FEES(®)) is comprehensive and time-consuming. Editing times of FEES protocols and attempts for efficiency maximization are unknown. Here, the protocol editing times of completed FEES examinations were determined. The present study reports the time savings and quality gains of a newly developed documentation system tailored to the FEES standard of Langmore. Four independent examiners analyzed twelve videos of FEES procedures, six without and six with the documentation system. Effectiveness of the documentation system was evaluated according to the times for total evaluation, interpretation, documentation, report writing, and for report completeness. The documentation system reduced editing times and increased report completeness with large effect sizes. Averaged total evaluation time decreased from 42 to 27 min, report completeness increased from 55 to 80%. The use of the documentation system facilitates and improves the assessment of the swallowing process.

How the brain repairs stuttering.

Stuttering is a neurodevelopmental disorder associated with left inferior frontal structural anomalies. While children often recover, stuttering may also spontaneously disappear much later after years of dysfluency. These rare cases of unassisted recovery in adulthood provide a model of optimal brain repair outside the classical windows of developmental plasticity. Here we explore what distinguishes this type of recovery from less optimal repair modes, i.e. therapy-induced assisted recovery and attempted compensation in subjects who are still affected. We show that persistent stuttering is associated with mobilization of brain regions contralateral to the structural anomalies for compensation attempt. In contrast, the only neural landmark of optimal repair is activation of the left BA 47/12 in the orbitofrontal cortex, adjacent to a region where a white matter anomaly is observed in persistent stutterers, but normalized in recovered subjects. These findings show that late repair of neurodevelopmental stuttering follows the principles of contralateral and perianomalous reorganization.

Computer-assisted documentation of the fiberoptic endoscopic evaluation of swallowing.

BACKGROUND: Because documentation and report writing in fiberoptic endoscopic evaluation of swallowing (FEES) is time consuming and susceptible to omissions, a software solution to ameliorate these problems by maintaining document quality is desirable. MATERIAL/METHODS: Based on the FEES procedure of Langmore, a documentation software (DS) which presents a digitized FEES recording and masks with precast text fields was designed to facilitate and unify data input. The oropharyngeal secretion scale of Murray and the penetration-aspiration scale of Rosenbek were integrated to increase comparability of dysphagia information. Four independent examiners analyzed 12 digitized FEES-recordings, 6 without and 6 with the DS, to determine its effect on the times needed for total evaluation, interpretation, documentation, report writing, and report completeness. RESULTS: The documentation software (DS) reduced the total evaluation time from 42 min to 18 min and increased the evaluation completeness from 55% to 95%, both with very large effect sizes. The time saving was mainly due to an automated report generation at the end of the analysis. CONCLUSIONS: The DS can be offered as a valuable and effective tool in daily clinical routine and for research purposes.

Testing the diagnostic value of electrical ear canal stimulation in cochlear implant candidates by functional magnetic resonance imaging.

Prior to cochlear implant (CI) surgery in children, the integrity of the auditory pathway is sometimes assessed by electrical ear canal stimulation (ECS). However, the evaluation of reactions as auditory is subjective. To test the prognostic value of ECS, functional magnetic resonance imaging (fMRI) was performed during ECS vicariously in 18 adult CI candidates. Activation of the primary auditory cortex was detected in 9 of 16 cases when auditory sensations during ECS occurred, and tended to be more bilaterally distributed in CI candidates than in normal-hearing controls. ECS sensations only tended to correlate with fMRI activations. However, solely frequency discrimination during electrical stimulation predicted CI outcome, but neither other auditory sensations nor fMRI activations did so satisfactorily, which limits the diagnostic value of these measures. Instead, preoperative residual hearing (nonamplified and amplified) was a robust predictor for CI benefit.

A randomized control trial to investigate the impact of the Lidcombe Program on early stuttering in German-speaking preschoolers.

UNLABELLED: In order to investigate whether the Lidcombe Program effects a short-term reduction of stuttered speech beyond natural recovery, 46 German preschool children were randomly assigned to a wait-contrast group or to an experimental group which received the Lidcombe Program for 16 weeks. The children were between 3;0 and 5;11 years old, their and both of their parents' native language was German, stuttering onset had been at least 6 months before, and their stuttering frequency was higher than 3% stuttered syllables. Spontaneous speech samples were recorded at home and in the clinic prior to treatment and after 4 months. Compared to the wait-contrast group, the treatment group showed a significantly higher decrease in stuttered syllables in home-measurements (6.9%SS vs. 1.6%SS) and clinic-measurements (6.8%SS vs. 3.6%SS), and the same increase in articulation rate. The program is considered an enrichment of currently applied early stuttering interventions in Germany. EDUCATIONAL OBJECTIVES: Readers will discuss and evaluate: (1) the short-term effects of the Lidcombe Program in comparison to natural recovery on stuttering; (2) the impact of the Lidcombe Program on early stuttering in German-speaking preschool children.

Health and human services for persons who stutter and education of logopedists in East-European countries.

UNLABELLED: The International Association of Logopedics and Phoniatrics (IALP) assessed the therapy status of fluency disorders, service opportunities, and education of logopedists (speech-language pathologists) with a mail survey in Eastern Europe. Information was collected on the following aspects: incidence, prevalence, availability of information, non-therapeutic support for persons who stutter (PWS), providers of diagnostics and therapy, cooperating professionals, therapy approaches, forms, goals, financing, early detection and prevention, training of professionals, specialization in stuttering therapy, needs for improving the situation of PWS, and problems which hinder better care. Stuttering therapy for children is available in many countries and is frequently provided by the educational system. Therapy for adults is provided best by the health services but is not satisfactorily available everywhere. Modern therapeutic approaches coexist with obsolete ones. Lack of resources, awareness, entitlement, and assessment of therapy effectiveness are pervasive problems. EDUCATIONAL OBJECTIVES: Readers will be able to describe and evaluate: (1) the therapy status of fluency disorders and service opportunities in various East-European countries; (2) the training of logopedists (speech-language pathologists); (3) specialization in stuttering therapy; and (4) the organizational services for PWS within the health and human service systems.

Severity of dysfluency correlates with basal ganglia activity in persistent developmental stuttering.

Previous studies suggest that anatomical anomalies [Foundas, A. L., Bollich, A. M., Corey, D. M., Hurley, M., & Heilman, K. M. (2001). Anomalous anatomy of speech-language areas in adults with persistent developmental stuttering. Neurology, 57, 207-215; Foundas, A. L., Corey, D. M., Angeles, V., Bollich, A. M., Crabtree-Hartman, E., & Heilman, K. M. (2003). Atypical cerebral laterality in adults with persistent developmental stuttering. Neurology, 61, 1378-1385; Foundas, A. L., Bollich, A. M., Feldman, J., Corey, D. M., Hurley, M., & Lemen, L. C. et al., (2004). Aberrant auditory processing and atypical planum temporale in developmental stuttering. Neurology, 63, 1640-1646; Jancke, L., Hanggi, J., & Steinmetz, H. (2004). Morphological brain differences between adult stutterers and non-stutterers. BMC Neurology, 4, 23], in particular a reduction of the white matter anisotropy underlying the left sensorimotor cortex [Sommer, M., Koch, M. A., Paulus, W., Weiller, C., & Buchel, C. (2002). Disconnection of speech-relevant brain areas in persistent developmental stuttering. Lancet, 360, 380-383] could be at the origin of persistent developmental stuttering (PDS). Because neural connections between the motor cortex and basal ganglia are implicated in speech motor functions, PDS could also be associated with a dysfunction in basal ganglia activity [Alm, P. (2004). Stuttering and the basal ganglia circuits: a critical review of possible relations. Journal of Communication Disorders, 37, 325-369]. This fMRI study reports a correlation between severity of stuttering and activity in the basal ganglia and shows that this activity is modified by fluency shaping therapy through long-term therapy effects that reflect speech production improvement. A model of dysfunction in stuttering and possible repair modes is proposed that accommodates the data presented here and observations previously made by us and by others.