Needle-like structures discovered on positively charged lightning branches.

Lightning is a dangerous yet poorly understood natural phenomenon. Lightning forms a network of plasma channels propagating away from the initiation point with both positively and negatively charged ends-called positive and negative leaders1. Negative leaders propagate in discrete steps, emitting copious radio pulses in the 30-300-megahertz frequency band2-8 that can be remotely sensed and imaged with high spatial and temporal resolution9-11. Positive leaders propagate more continuously and thus emit very little high-frequency radiation12. Radio emission from positive leaders has nevertheless been mapped13-15, and exhibits a pattern that is different from that of negative leaders11-13,16,17. Furthermore, it has been inferred that positive leaders can become transiently disconnected from negative leaders9,12,16,18-20, which may lead to current pulses that both reconnect positive leaders to negative leaders11,16,17,20-22 and cause multiple cloud-to-ground lightning events1. The disconnection process is thought to be due to negative differential resistance18, but this does not explain why the disconnections form primarily on positive leaders22, or why the current in cloud-to-ground lightning never goes to zero23. Indeed, it is still not understood how positive leaders emit radio-frequency radiation or why they behave differently from negative leaders. Here we report three-dimensional radio interferometric observations of lightning over the Netherlands with unprecedented spatiotemporal resolution. We find small plasma structures-which we call 'needles'-that are the dominant source of radio emission from the positive leaders. These structures appear to drain charge from the leader, and are probably the reason why positive leaders disconnect from negative ones, and why cloud-to-ground lightning connects to the ground multiple times.

[Reconstruction of isolated orbital floor fractures with a prefabricated titanium mesh]. / Versorgung isolierter Orbitabodenfrakturen - Rekonstruktion mit präfabriziertem Titanmesh.

PURPOSE: Concerning safety and efficiency in surgery of isolated orbital floor fractures, several treatment modalities are being discussed. It is a matter of recent interest that prefabricated titanium meshes provide significant advantages. The purpose of this study was to review the usability of the MatrixORBITAL® plate. MATERIAL AND METHODS: In a prospective study we evaluated 10 patients (June 2011 to November 2013) with an isolated orbital floor fracture. All patients in the study group had undergone reconstruction with the MatrixORBITAL® plate. For purposes of analysis were recorded: age, gender, fracture category according to Jaquiéry et al. (2007), duration of surgery, complications, globe motility (Harms wall), exophthalmometry, function of the infraorbital nerve, evaluation of facial symmetry and aesthetic as well as personal contentment of the patient. A reference group received a PDS® sheet, an antral balloon or other materials. RESULTS: In the study group (2 women and 8 men aged between 26 and 83 years) all cases presented a large disruption of the orbital floor (> 2 cm2 bony defect; category II-III). Volume changes were universally associated with diplopia, but only in two cases with an entrapment of the inferior rectus muscle. The mean duration of the operation was 110 minutes (minimum 50, maximum 135 minutes). Postoperatively diplopia was decreasing in all cases. None of the patients had a significant impairment of visus and no reoperation was necessary. The analysis of functional outcomes between the groups mesh, PDS sheet and antral balloon revealed no significant differences. CONCLUSIONS: Based on this experience and due to good intraoperative handling, the authors recommend the prefabricated titanium plate in the treatment of isolated orbital wall fractures or in combination with the medial wall despite the material costs.

[Renaissance of pedicled flaps in oral and maxillofacial surgery]. / Renaissance gestielter Fernlappen in der Mund-Kiefer-Gesichts-Chirurgie.

A retrospective analysis in the period 2007 to 2011 included 71 surgically treated patients for carcinoma of the head and neck region and subsequent reconstruction with 36 pedicled distant flaps and 47 free flaps. Patient specific parameters of data collection with SPSS 17.0 were age and sex distribution, TNM stage and treatment. The specific type of flap reconstruction, duration of surgery, complications, intensive care and inpatient treatment were recorded. The results showed that the healing process was uneventful in 26 (72.2 %) pedicled flaps, 14 (38.9 %) pedicled flaps were transplanted in a preoperatively irradiated area of the head and neck region and in 86.0 % with a positive healing process. Tumor stage, general physical condition of the patient and type of therapy are the key parameters for the choice of reconstruction.

[Trauma of periorbital soft tissue. Reconstruction with regard to functional and aesthetic aspects]. / Trauma der periorbitalen Weichteile. Rekonstruktion unter funktionellen und ästhetischen Gesichtspunkten.

Complex midfacial trauma requires interdisciplinary management. A wide range of reconstructive procedures are needed and if necessary secondary and even tertiary interventions should be performed at the appropriate time. We present the case of a 45-year-old man who was involved in a car accident and presented with severe injuries to the periorbital soft tissue. The focus was on the reconstruction of this sensitive region with regard to functional and aesthetic aspects. In view of the severity of the injuries the final clinical status is considered to be very important. Special issues and pitfalls in the reconstruction of trauma cases and potential management are discussed.

Analysis of Streamline Separation at Infinity Using Time-Discrete Markov Chains.

Existing methods for analyzing separation of streamlines are often restricted to a finite time or a local area. In our paper we introduce a new method that complements them by allowing an infinite-time-evaluation of steady planar vector fields. Our algorithm unifies combinatorial and probabilistic methods and introduces the concept of separation in time-discrete Markov-Chains. We compute particle distributions instead of the streamlines of single particles. We encode the flow into a map and then into a transition matrix for each time direction. Finally, we compare the results of our grid-independent algorithm to the popular Finite-Time-Lyapunov-Exponents and discuss the discrepancies.

[Intraoperative adverse events in minor oral surgery. Risk analysis]. / Intraoperative Komplikationen in der zahnärztlichen Chirurgie. Risikoanalyse.

AIM OF THE STUDY: The aim of this prospective study was to evaluate oral surgical procedures performed as day surgery under local anesthesia. We examined patients' general condition, and besides checking for intraoperative complications we analyzed postoperative bleeding in patients with hemostatic disorders. PATIENTS: The patient population consisted of 1540 patients (797 female, 743 male), who underwent a total of 2055 minor oral surgical procedures over a 5-year period (1998-2002). Before the treatment started a data file was made for each patient, which contained information on his or her past medical history, concomitant medication, why the operation was indicated, premedication, anesthetic and surgical techniques applied, and postoperative treatment. RESULTS: Systemic pathologies influencing surgical decisions were found in 316 patients (20.5%), affecting 676 interventions (32.9%). In 109 patients (5.3% of the 2055) altered hemostasis was found. The surgical procedures recorded were: (operative) tooth extraction (n=394), interventions for surgical conservation of teeth (n=272), treatment for cysts (n=140), surgical revisions (n=46) and preprosthetic surgery (n=19). Passing complications, mostly systemic in nature, occurred during 27 sessions of local anesthesia (1.3%). There were 87 adverse events intraoperatively (4,2%), most of which were confined to the surgical field; specifically 15% of these complications took the form of hemorrhage. We observed no significant correlation between the occurrence of intraoperative complications and patients' gender, predisposing systemic pathologies including bleeding disorders, or age. Postoperative hemorrhage was observed significantly more frequently in patients with impaired hemostasis and required admission to hospital for inpatient treatment in 2 cases. CONCLUSION: According to our investigation, oral surgery can be performed in patients with compromised general condition with as few intraoperative complications as in patients with no general medical problems. However, in individual cases specific risk factors can be present and oral surgery may be temporarily contraindicated, at least as day surgery.

Family factors and sampling approach differentially influence attention deficit/hyperactivity disorder subtypes.

A widely used statistical method to test for genetic association is the transmission disequilibrium test (TDT) using two parent-proband trios. West et al(1) have presented evidence from clinically ascertained ADHD families that children from trios were less likely to have DSM-IV combined subtype ADHD and conduct disorder. They suggest that the exclusion of parent-proband duos could reduce the power of the TDT and similar tests to detect susceptibility genes for this subtype of ADHD. We sought to test this hypothesis in a population-based sample of twin families, while controlling for the effects of other proband and family characteristics in a multivariant logistic regression framework using both latent class and DSM-IV ADHD subtype definitions. For both latent class and DSM-IV defined combined and inattentive ADHD, sex of the proband and comorbid conduct disorder or oppositional defiant disorder, significantly predicted diagnosis. For latent class and DSM-IV defined combined subtype, younger age also significantly predicted ADHD subtype. Latent class and DSM-IV defined combined subtype ADHD with comorbid conduct disorder was significantly less common in children from trios while conduct disorder without ADHD did not differ in frequency between families with zero, one or two participating parents.

Developmental sequence from disruptive behavior diagnosis to adolescent alcohol dependence.

OBJECTIVE: The authors sought to clinically describe the relationship of disruptive behavior disorders with both alcohol dependence and the use of a variety of substances. METHOD: The Child Semi-Structured Assessment for the Genetics of Alcoholism was used to collect data on 54 adolescents with a diagnosis of alcohol dependence. The frequency and age at onset of the disruptive behavior disorder diagnoses were examined as well as age at first use of alcohol, tobacco, marijuana, and other street drugs. RESULTS: Nearly three-quarters of the alcohol-dependent adolescents had at least one disruptive behavior disorder diagnosis. Attention deficit hyperactivity disorder (ADHD) typically occurred first, followed by conduct disorder. Substance use began with alcohol or tobacco, followed by marijuana and then other street drugs. Alcohol dependence began significantly later than the onset of either ADHD or conduct disorder and significantly later than the first use of tobacco. CONCLUSIONS: Disruptive behavior diagnoses, particularly conduct disorder, typically precede the initiation of use of a variety of substances that, in turn, precede the diagnosis of alcohol dependence in adolescents.

Suicide attempts in an adolescent female twin sample.

OBJECTIVE: To examine suicide attempts in an epidemiologically and genetically informative youth sample. METHOD: 3,416 Missouri female adolescent twins (85% participation rate) were interviewed from 1995 to 2000 with a telephone version of the Child Semi-Structured Assessment for the Genetics of Alcoholism, which includes a detailed suicidal behavior section. Mean age was 15.5 years at assessment. RESULTS: At least one suicide attempt was reported by 4.2% of the subjects. First suicide attempts were all made before age 18 (and at a mean age of 13.6). Major depressive disorder, alcohol dependence, childhood physical abuse, social phobia, conduct disorder, and African-American ethnicity were the factors most associated with a suicide attempt history. Suicide attempt liability was familial, with genetic and shared environmental influences together accounting for 35% to 75% of the variance in risk. The twin/cotwin suicide attempt odds ratio was 5.6 (95% confidence interval [CI] 1.75-17.8) for monozygotic twins and 4.0 (95% CI 1.1 -14.7) for dizygotic twins after controlling for other psychiatric risk factors. CONCLUSIONS: In women, the predisposition to attempt suicide seems usually to manifest itself first during adolescence. The data show that youth suicide attempts are familial and possibly influenced by genetic factors, even when controlling for other psychopathology.

Familiality and heritability of subtypes of attention deficit hyperactivity disorder in a population sample of adolescent female twins.

OBJECTIVE: Attention deficit hyperactivity disorder (ADHD) is a highly heritable but clinically heterogeneous syndrome. The study examined the familiality and heritability of ADHD subtypes as defined by DSM-IV and by latent-class analysis in a population sample of adolescent female twins. METHOD: To determine which elements of ADHD cluster together, latent-class analysis was applied to data obtained from parents on the 18 DSM-IV ADHD symptoms in 4,036 female twins age 13-23 years in a population sample identified from the registry of all births in Missouri for the years 1968-1996. Relative risk and odds ratios were used to assess within-subtype and between-subtype familiality and heritability of both DSM-IV and latent-class ADHD subtypes. RESULTS: Latent-class analysis was most compatible with the existence of three mild and three severe classes of ADHD symptoms in the general population. The three severe classes showed moderate overlap with DSM-IV ADHD subtypes. The primarily inattentive and combined subtypes of DSM-IV ADHD co-clustered within families. The primarily hyperactive/impulsive DSM-IV subtype and the individual latent-class analysis subtypes did not co-cluster. Subtypes defined by both approaches were highly heritable. CONCLUSIONS: Unlike DSM-IV subtypes of ADHD, latent-class ADHD subtypes appear to be independently transmitted in families. These classes may be more appropriate targets for molecular genetic studies of ADHD.

Latent class analysis of ADHD and comorbid symptoms in a population sample of adolescent female twins.

Attention-deficit/hyperactivity disorder (ADHD) is a phenotypically heterogeneous and highly heritable syndrome. which commonly co-occurs with other psychiatry disorders. To assess the role of genetic influences in ADHD, we used latent class analysis (LCA) to identify subtypes of ADHD taking into account its comorbidity with separation anxiety, oppositional defiant disorder (ODD), and three major depression symptoms. A structured interview was used to collect diagnostic data from a population sample of 2,904 adolescent female twins and their parents. LCA was applied to ADHD. separation anxiety. ODD symptom profiles obtained from the twins' parents, and major depression symptom profiles obtained from the twins' self-report. Odds ratios were used to test for familiality of class membership by examining the effect of zygosity on twin concordance within and between latent classes. Structural equation modeling was used to compute heritabilities for latent class membership. LCA revealed three ADHD categories of clinical interest: an inattentive subtype without comorbidity, a second inattentive subtype with increased number of ODD symptoms. and a combined inattentive/hyperactive-impulsive type with elevated levels of ODD, separation anxiety, and depressive symptoms. LCA also distinguished an ODD class and a separation anxiety class, each without increased levels of other comorbid symptoms; a second ODD class co-occurring with increased separation anxiety and depression symptoms; and a pure depression class. Odds ratios for MZ contrasted with DZ twin concordance for individual latent class membership ranged from 2.5 to 19.4. Overall, 66% of MZ pairs, but only 36% of DZ pairs, were assigned to the same latent class, consistent with a genetic hypothesis for latent class membership. Individual class membership was shown to have high heritability ranging from .34-.85. The pattern of latent classes suggested that in the general female adolescent population, there are three highly heritable ADHD subtypes, two of which are comorbid with other disorders. These classes were consistent with a genetic hypothesis for ADHD, with each class potentially reflecting a unique genetic subtype.

Lack of association of dopamine D4 receptor gene polymorphisms with ADHD subtypes in a population sample of twins.

Attention-deficit hyperactivity disorder (ADHD) is a common, highly heritable syndrome of childhood characterized by problems with inattention, hyperactivity, and impulsivity. A variety of case control and family-based transmission distortion genetic studies of ADHD have focused on the possible involvement of polymorphisms of the DRD4 receptor gene. The majority of studies have examined the association of variously defined ADHD with an exon 3 polymorphism containing a variable number of imperfect 48 base pair repeats. Recently, McCracken et al. [2000: Mol Psych 5:531-536] reported an association of the DSM-IV primarily inattentive ADHD subtype with a 5' 120 base pair repeat polymorphism in the DRD4 gene. In this report, we test for the possible association of these two polymorphisms with population-derived samples of DSM-IV ADHD subtypes. Furthermore, we extend previous studies by testing for associations with ADHD subtypes derived from latent-class analysis of interview responses. In contrast to most, but not all, previous studies, we failed to demonstrate any significant association of the exon 3 7-repeat allele with ADHD. Nor did we replicate the association of the 5'120 base pair repeat polymorphism. We do find a significant association of the exon 3 3-repeat allele with a novel talkative/impulsive latent-class-defined subtype of ADHD.

Evidence for a locus on chromosome 1 that influences vulnerability to alcoholism and affective disorder.

OBJECTIVE: Depression (major depression or depressive syndrome) is more prevalent in alcoholic than in nonalcoholic subjects in families with multiple members with alcoholism studied as part of the Collaborative Study on the Genetics of Alcoholism (National Institute on Alcohol Abuse and Alcoholism). First-degree relatives of probands with comorbid alcoholism and depression have a higher prevalence of both disorders than relatives of probands with alcoholism alone, and both groups have a higher prevalence than the relatives of comparison subjects selected without regard to psychopathology. Data from the collaborative study were used to test three phenotypes (comorbid alcoholism and depression, alcoholism or depression, and depression) for genetic linkage. METHOD: Genome-wide sibling-pair linkage analyses were performed with the phenotypes comorbid alcoholism and depression, alcoholism or depression, and depression (major depression or depressive syndrome). Analyses were performed in two data sets (initial and replication data sets) from subject groups ascertained with identical criteria, as well as in the combined data set. RESULTS: Peak lod scores on chromosome 1 (near 120 centimorgan) for the alcoholism or depression phenotype were 5.12, 1.52, and 4.66 in the initial, replication, and combined data sets, respectively. The corresponding lod scores on chromosome 2 were 2.79, 0.20, and 3.26; on chromosome 6, they were 3.39, 0.00, and 0.92; and on chromosome 16, they were 3.13, 0.00, and 2.06. Lod scores on chromosome 2 for the comorbid alcoholism and depression phenotype in the three data sets were 0.00, 4.12, and 2.16, respectively. CONCLUSIONS: The results suggest that a gene or genes on chromosome 1 may predispose some individuals to alcoholism and others to depression (which may be alcohol induced). Loci on other chromosomes may also be of interest.

Risk domains associated with an adolescent alcohol dependence diagnosis.

AIMS: To determine the contribution of familial, interpersonal, academic and early substance use factors to relative risk for an alcohol dependence (AD) diagnosis in adolescents. METHODS: Information on 619 adolescents and their 390 sets of biological parents was obtained using the adolescent version of the Child Semi-Structured Assessment for the Genetics of Alcoholism (C-SSAGA) and the adult counterpart of this instrument, the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA). The C-SSAGA elicits a wide range of environmental, social, and psychiatric diagnostic information. Specific domain scale scores associated with an adolescent AD were computed, and generalized estimating equations (GEE) modeling was used to determine the odds ratio (relative risk) of the specified risk domains for an alcohol dependence diagnosis. FINDINGS: Risk factors for a DSM-III-R AD diagnosis included being at least 16 years of age, as well as negative parent-child interactions, school and personal-related difficulties (including the presence of an externalizing or internalizing DSM-III-R non-alcohol-related diagnosis), and early experimentations with a variety of substances. CONCLUSIONS: An array of familial, interpersonal, academic and early substance use factors were strongly associated with adolescent AD. Given the findings of this study, further research to determine temporal relationships that might influence the onset of adolescent alcohol dependence is warranted.

The care-based ethic of Nazi medicine and the moral importance of what we care about.

This article reports on an inquiry into ideas used to justify the shift of medical ethos in Germany prior to and during the Nazi era, specifically the principles of care advocated by Erwin Liek and Karl Kotschau, the era's most influential medical theorists, who argued that commitments to care of individual sick persons (Fursorge) had to give way to a preventive care that respects emerging needs of the entire society (Vorsoge). The article examines both the socio-cultural factors that shaped, and the far-reaching effects of, this manipulation of care. It argues that we should be attentive to the meaning and requirements of the care revealed in this debate, the ancient Greek idea of care as a concerned moral option.

No association of the dopamine transporter gene 3' VNTR polymorphism with ADHD subtypes in a population sample of twins.

Dopamine pathway genes have been the subject of a variety of studies testing the association of candidate genes and liability for attention-deficit hyperactivity disorder (ADHD). Due to the known effects of stimulant medications such as methylphenidate on the dopamine transporter, a variety of case control and family-based transmission distortion genetic studies of ADHD have focused on DAT1 polymorphisms. The most widely reported positive finding has been with a variable number of tandem repeats (VNTR) polymorphism of unknown function in the 3' untranslated region of the DAT1 gene. In this report, we test for association of alleles of this polymorphism with ADHD using population-derived samples of twins. We use the transmission disequilibrium test and ADHD subtypes defined by both DSM-IV and latent class criteria. We fail to demonstrate any significant association or trend for association of any of the VNTR alleles with any of the variously defined ADHD subtypes.

Social phobia in a population-based female adolescent twin sample: co-morbidity and associated suicide-related symptoms.

BACKGROUND: This report attempted to replicate and extend prior work examining social phobia (SP), co-morbid psychiatric illnesses, and the risk of suicidal ideation and suicide attempts incurred by their adolescent sufferers. METHODS: SP, alcohol dependence (ALD) and major depressive disorder (MDD) diagnoses, and suicide-related symptoms, were assessed in a population-based adolescent female twin sample. The differentiation of risks as a function of co-morbidity was explored. A trivariate model was fitted to estimate sharing of genetic and environmental vulnerability between SP and co-morbid disorders. RESULTS: The lifetime prevalence of SP was 16.3 %. Significant risk for co-morbid MDD (OR = 3.2) and ALD (OR = 2.1) was observed. Strong evidence for shared genetic vulnerability between SP and MDD (respective heritabilities 28%, 45%; genetic r = 1.0) was observed with moderate support noted for similar sharing between SP and ALD (genetic r = 0.52, heritability for ALD 63%). SP with co-morbid MDD was associated with elevated risk for ALD and for suicide-related symptoms. CONCLUSIONS: SP is a common illness often followed by co-morbid MDD and ALD. SP with comorbid MDD predicts a substantially elevated risk of ALD and suicide-related symptoms, stressing the need for early SP detection.

Further evidence that the family assessment device should be reorganized: response to Miller and colleagues.

Ridenour, Daley, and Reich's (1999) factor analyses of the Family Assessment Device (FAD) indicated that the FAD be reorganized. Miller and colleagues (2000) contend that the FAD be used in its original format based on the FAD's theoretical foundation; however, this does not preclude the importance of scientific scrutiny of an instrument's construct validity to determine how well an instrument represents its theoretical base. Subscale factor analyses (exploratory and confirmatory), item-level factor analysis, and the clinical and psychometric studies cited by Miller and colleagues suggest a more parsimonious FAD configuration and were consistent with Ridenour and colleagues' factor analyses.

Identity structure, narrative accounts, and commitment to a volunteer role.

Degree of commitment was explored in relation to core self and role-identity. Thirty-one American emergency medical technicians (EMTs) described themselves in the EMT role (EMT now) and the way they anticipated they would be in the future (EMT future) by selecting items from an adjective checklist. Participants also described "real me," "ideal me," and "ought me." Ratings of commitment and extranormative activity were also obtained. Finally, participants described a positive and a negative episode they had experienced as an EMT in an open-ended question that was coded for task and relational content. Each participant's checklist data set was individually analyzed using HICLAS, a clustering algorithm for binary data (P. DeBoeck, S. Rosenberg, & I. Van Mechelen, 1993). Results indicate that the similarity between EMT now and real me best predicted activity and the similarity between EMT future and real me best predicted commitment (positive correlations in both cases). Older, more experienced EMTs tended to describe positive episodes in relational terms, whereas younger, less experienced EMTs described positive experiences in task-oriented terms.