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The 19th annual symposium of the International Isotope Society's United Kingdom Group took place at the Wellcome Genome Campus, Hinxton, Cambridge, UK on Thursday 14th October 2010. The meeting was attended by around 80 delegates from academia and industry, the life sciences, chemical, radiochemical and scientific instrument suppliers. Delegates were welcomed by Dr. Ken Lawrie (GlaxoSmithKline, UK, chair of the IIS UK group). The subsequent scientific programme consisted of oral and poster presentations on isotopic chemistry and applications of labelled compounds, or of chemistry with potential implications for isotopic synthesis. Both short-lived and long-lived isotopes were represented, as were stable isotopes. The symposium programme was divided into a morning and an afternoon session chaired by Prof. Chris Willis (University of Bristol, UK) and Dr. Nigel Botting (University of St Andrews, UK) respectively. In addition, a short presentation on the formation of Special Interest Groups within the International Isotope Society was given by Dr. George Ellames (Covance, UK), who asked members with particular isotopic interests to contact him (george.ellames@covance.com) if they would like to be involved in forming or participating in these groups. The UK meeting concluded with remarks from Dr. Ken Lawrie (GlaxoSmithKline, Stevenage, UK). This year's UK symposium had an excellent level of sponsorship, and the symposium should prove self-financing. The location and facilities of the Hinxton campus again proved very popular and the next IIS UK symposium is provisionally planned for 18th October 2011 at the same venue.

Bead-on-plate welding tests were performed using a 600 W fiber-delivered fiber laser. Uniform, high-aspect-ratio keyhole welds were observed in 1018 low-carbon steel, 1100 aluminum, and 304 stainless steel. The Rosenthal two-dimensional thermal model for a moving-line heat source was effective in predicting weld width for both partial-penetration and full-penetration welds. By setting the temperature at the perimeter of the keyhole equal to the vaporization temperature, this same model provided a first-order estimate of the weld depth for partial-penetration welds, as well. The two-dimensional model was used to calculate the steady-state temperature field associated with the welding process as well as the temporal thermal history of points in the weld pool and in the heat-affected zone next to the weld pool. A comparison of calculated weld-bead geometries with dimensions scaled from micrographs of bead cross sections showed reasonable agreement.

Phrenic nerve paralysis due to iatrogenic injury is not uncommon in neonates. We report an unusual case of acquired unilateral paralysis of the diaphragm in a very-low-birth-weight infant, associated with a thrombus secondary to percutaneous subclavian vein catheterization. Conservative management resulted in complete resolution of the paralyzed diaphragm.

This whole rock and silicate mineral study focuses on the genesis of the Merensky reef sequence, as well as the footwall and hanging wall norites at an area of Rustenburg Platinum Mines in a demonstrably normal (undisturbed) environment. Continuous sampling provides major and trace element variations and mineral compositions and allows an evaluation of the post- liquidus processes which affected the sequence. Following the formation of liquidus phases three stages are envisaged to have modified the rocks. These are (a) migration of fluid during early compaction of cumulates, (b) circulation of fluids within the crystal mush, and (c) reaction and solidification of trapped liquid. Liquidus compositions are nowhere preserved in the sequence. A strong link is demonstrated between orthopyroxene compositions (e.g. Mg# and TiO2) and the incompatible trace element content of the whole rocks. The final amount of trapped liquid is shown to have been variable but never exceeded 10%. Calculated liquidus (pre-equilibration) orthopyroxene compositions show an up- sequence progression of evolving compositions from the footwall norite to the hanging wall norite. Initial Sr isotopic values do not support a simple magma mixing model by which radiogenic Main Zone magma mixes with that of the Critical Zone at the level of the Merensky reef. There is evidence that the hanging wall norite formed from a much more evolved magma. These conclusions have implications for the distribution and origin of the PGE-enriched Merensky reef package.

We studied 45 patients who had autonomic failure with computed tomography, magnetic resonance imaging and positron emission tomography with [18F]fluorodeoxyglucose to characterize the neuroimaging features of multiple system atrophy and pure autonomic failure and determine the utility of these techniques in distinguishing multiple system atrophy from pure autonomic failure. There were 30 patients with multiple system atrophy and 15 with pure autonomic failure. In the multiple system atrophy group, eight patients had mainly cerebellar signs, seven extrapyramidal and 15 had combinations of cerebellar and extrapyramidal signs. Cerebellar atrophy on computerized tomography and magnetic resonance imaging, signal hypointensity in the posterolateral putamen on magnetic resonance imaging and a generalized reduction in glucose utilization rate with positron emission tomography with [18F]fluorodeoxyglucose, were the main findings and were seen only in the patients with multiple system atrophy. Decreased glucose utilization (hypometabolism) was most prominent in the cerebellum, brainstem, striatum and frontal and motor cortices. These results indicate clear differences, using neuroimaging studies, between multiple system atrophy and pure autonomic failure.

This investigation examined children's capacity to decode verbal and nonverbal emotional stimuli. Children with externalizing behavioral symptoms were compared to two types of controls, including chronically ill and normally developing children. Children were requested to identify whether video scenes were happy, angry, sad, or neutral, across four different modalities including verbal, prosody, facial, and combined. Findings were that chronological age was a significant predictor of children's ability to decode emotions with older children having better developed abilities than their younger peers. Verbal intelligence also was found to be a significant predictor of the ability to decode facial expressions and combined scenes. Although the data did not support the original hypotheses that children with externalizing behavior disorders would be less accurate than controls in the decoding of emotions, findings did support a developmental progression of decoding accuracy. Recommendations within the limitations of the study design are provided which support a developmental framework in children's acquisition of the decoding of emotions.

Sickle cell disease (SCD), a class of genetic disorders characterized by abnormal, sickled red blood cells, is a chronic illness that results in progressive cerebrovascular disease. Neurocognitive sequelae of clinically apparent cerebrovascular accidents in children with SCD are characterized by pervasive impairments, including decrements in general intellectual functioning, language and verbal abilities, visual-motor and visual-spatial processing, memory, academic achievement, and processing of subtle prosodic information. In contrast, subtle neurocognitive deficits in the areas of attention and concentration, executive function, and visual-motor speed and coordination appear to be associated with silent infarcts that are not necessarily detected on physical examination. Investigation of the disease course and associated neurocognitive sequelae suggest a disease-specific model of neuropsychological impairment. Recommendations are made for clinical and research efforts in the field of pediatric neuropsychology.

The authors examined the associations between parental variables and child syncope (fainting). Children ages 7 to 18 years undergoing tilt-table testing for neurocardiogenic syncope (NCS) at a pediatric cardiac center served as participants (N = 56). Results revealed that fathers' shortness of breath and overall psychological distress were significantly related to syncope frequency and emergency room (ER) visits for girls. Mothers' overall psychological distress, depressive symptoms, and shortness of breath were associated with boys' frequency of syncope and ER visits. Fathers' psychological factors were highly correlated with syncope for the children diagnosed negative for NCS. The frequency of children's syncope was higher in stepfamilies than in homes with both biological parents, and the correlations between children's syncope and the stepfathers' psychological symptoms were greater than for the children and their biological fathers in intact families. The role of parental psychological factors on child syncope is supported.

Interleukin 6 (IL-6), the major growth factor for myeloma cells, signals through the activation of signal transducers and activators of transcription (STAT) proteins. An important step in the malignant progression of murine plasmacytomas is the transition from dependence on IL-6 to a state of IL-6 independence. To elucidate the mechanism whereby IL-6 independence occurs, intracellular signaling events elicited by IL-6 in both IL-6-dependent and -independent plasmacytomas and hybridomas were compared. It was found that STAT3, a key molecule involved in IL-6 signaling, was constitutively activated and phosphorylated in IL-6-independent cell lines compared to the IL-6-dependent cells. Further comparison of upstream signaling pathways revealed that JAK-1 was constitutively present in anti-phosphotyrosine immunoprecipitates of IL-6-independent cells; gp130 was constitutively phosphorylated in a subset of IL-6-independent plasmacytomas, whereas other IL-6-independent lines showed no detectable gp130 phosphorylation in the absence of exogenous IL-6. Secretion of a factor capable of supporting the growth of IL-6-dependent cells was observed in one of the IL-6-independent plasmacytomas, but not in others, making an autocrine mechanism an unlikely explanation for IL-6 independence. These findings provide evidence that the constitutive activation of STAT3, either in the absence of detectable receptor-proximal events or associated with the concomitant activation of gp130, can contribute to the process of IL-6 independence.

To determine the clinical presentation, histopathologic features, and outcome of biopsy-proven allergic gastroenteropathy (AGE) in preterm infants. We hypothesized that AGE is a more frequent cause of gastrointestinal disease in this population than previously suspected.The retrospective portion of the study, from 1992 to 1997, included preterm infants37 weeks' gestation who underwent biopsy because of suspected AGE. The prospective portion, from January to December 1998, included 20 infants undergoing endoscopy and biopsy because of suspected AGE.Twenty-five infants (12 retrospective/13 prospective) with mean gestational age of 29 weeks at birth and mean postnatal age at diagnosis of 78 days were diagnosed with AGE. Three clinical patterns of presentation were noted: group 1, gastroesophageal reflux disease (n = 5); group 2, non-specific feeding intolerance (n = 8); and group 3, lower gastrointestinal bleeding (n = 12). Ten patients had negative biopsy findings (3 retrospective/7 prospective) and had clinical features indistinguishable from those of groups 1 and 2. Patients in group 3 were most likely to have positive biopsy findings (12 of 12). Fifteen patients responded to a casein hydrolysate formula, and 10 patients required an amino acid-based formula. Patients with AGE who had eosinophilic infiltration and villous atrophy took longer to recover than those with eosinophilic infiltration alone (P.03). Subsequently, most have tolerated formula challenges and are currently tolerating cow's milk.AGE may be an under-recognized cause of gastrointestinal symptoms in preterm infants. Confirmation with endoscopy and biopsy can be done safely and provides the basis for appropriate dietary management.

The authors examined the association of psychological adjustment, styles of coping, and disease severity for children with recurrent syncope. Participants were 44 children and adolescents with a history of recurrent syncope and 40 healthy comparison control children. Dependent variables were measures of internalizing adjustment (e.g., anxiety, depression, withdrawal) reported by children and their parents and styles of coping reported by children. Parents reported higher frequencies of the internalizing of behavioral symptoms (i.e., anxiety, withdrawal) for children with recurrent syncope compared with their healthy counterparts. Children's self-reports did not reveal significant differences between the syncope and comparison groups in psychological adjustment and styles of coping. The authors conclude from these findings that adjustment difficulties, including symptoms of anxiety and social withdrawal, may occur with recurrent syncope. Implications for clinical practice and future research are discussed.

Social skills and psychological adjustment for survivors of childhood cancer were investigated. Cancer survivors included 42 children and adolescents ranging in age at evaluation from 6 to 18 years with a mean age of 13.1 years. Measures included teacher and parent ratings of social skills and adjustment and parent ratings of family functioning. The findings showed that social skills and psychological adjustment as rated by both parents and teachers were primarily associated with academic functioning. In addition, family cohesiveness was found to account for nearly one third of the variance in survivors' adjustment when rated by teachers, and length of time off treatment accounted for a significant percentage of the variance in children's adjustment when rated by parents. The findings underscore the importance of a multi-informant approach to the assessment of psychological adjustment of pediatric cancer survivors and demonstrate the role of learning difficulties and family functioning in influencing social skills and adjustment for these children and adolescents.

Human sexuality can be defined as including the physical characteristics of and capacities for specific sex behaviors, together with psychosocial values, norms, attitudes, and learning processes that influence these behaviors. It also includes a sense of gender identity and related concepts, behaviors, and attitudes about the self and others as women or men in the context of one's society. At the dawn of the new century, adolescent sexuality remains a topic of concern to adults throughout the world. This concern is not unique to this new age. In each era of recorded history, adults have been concerned about adolescent sexual behavior, particularly sexual intercourse and its consequences. Things have not changed all that much in the realm of adolescent sexual behavior. What has changed is our ability to prevent the serious consequences of this behavior and, hopefully, to help adolescents avoid behaviors that put them at risk for the negative consequences of expressing their burgeoning sexuality. This article reviews the major influences on adolescents developing' sexuality, the data on adolescent sexual activity, some tips on caring for adolescents comprehensively, and ends with some predictions of how this issue will be addressed in the new century.

Monocyte/macrophage cell lines are fastidious cells commonly used in transient transfection experiments. In the course of a study of gene regulation by lipopolysaccharide (LPS), we have compared several methods for DNA-mediated cell transfection to determine which would be optimally applicable to the macrophage line, RAW 264.7. Both the response level (LPS inducibility) and the degree of inter-assay variation were evaluated for each transfection technique. The following methods were compared: LIPOFECTIN®, LIPOFECTAMINE™, LIPOFECTAMINE PLUS™, SuperFect™, Ca3(PO4)2 DNA co-precipitation, DEAE dextran-mediated transfection and electroporation. The transfected plasmid DNA included a luciferase reporter construct containing the junB minimal promoter under the control of an LPS-inducible 1300-bp regulatory fragment downstream of junB 5′-flanking sequence, as well as a β-galactosidase reporter construct under the adenovirus promoter and enhancer used as an internal control. Electroporation, followed by a resting period of 16–24 h before stimulation with LPS, had the highest inducibility of all methods. DEAE dextran and Ca3(PO4)2 precipitation showed the least and the greatest inter-assay variation, respectively. For all other methods, inter-assay variability fell within this range. The results presented may serve as both a general reference and a guide for reporter gene studies in this or other macrophage cell lines.

Behavioral deficits are often noted in children with fetal alcohol syndrome (FAS) and other individuals with prenatal alcohol exposure, including mental retardation, learning problems, social problems, and deficits in attention. Because attention deficit, hyperactivity disorder (ADHD) has been diagnosed so frequently in children with FAS and other alcohol related birth defects, there has been speculation that alcohol is an etiological factor in ADHD. To examine the relationship between behavior characteristics of children with fetal alcohol exposure and those seen in children with a diagnosis of ADHD, 149 low socioeconomic status (SES), African-American children (mean age = 7.63 years) were given a battery of neuropsychological and behavioral tests. One hundred and twenty-two were a sub-sample from a longitudinal study of prenatal alcohol exposure, whereas twenty-seven were identified in an ADHD Clinic. Children were given two sets of tests: (1) "traditional model" of conventional behavioral and psychiatric measures of ADHD and externalizing behavior; and (2) measures of neurocognitive functioning reflecting a four-factor model of the neurological basis of the components of attention (Mirsky AF, in Integrated Theory and Practice in Clinical Neuropsychology, Hillsdale, NJ, Lawrence Erlbaum Associates, 1989). Results indicated that children with the physical characteristics associated with prenatal alcohol exposure and those with a diagnosis of ADHD had equivalent intellectual abilities with both clinical groups performing more poorly than contrast children from the same SES and ethnic groups. However, there were clear distinctions on behavioral and neurocognitive measures between the two clinical groups with those with ADHD performing more poorly on conventional tests sensitive to attentional problems and conduct disorder. When these two groups were compared on measures designed to measure the model of the four factors of attention by Mirsky, they were noted to have distinct patterns of deficits. These results suggested that the alcohol-affected children did not have the same neurocognitive and behavioral characteristics as children with a primary diagnosis of ADHD.

Present-day Nd:YAG lasers are inadequate for carrying out precision drilling and cutting operations in advanced aerospace materials such as high-nickel alloy metals and graphite:epoxy composites. The high-brightness beams from next-generation solid-state lasers promise to overcome many of the deficiencies of present-day lasers, enabling improved small-hole drilling and improved low-heat-affected-zone cutting. This paper reviews examples of processing tests carried out with high-brightness 1.06 micron beams and 0.53 micron beams from advanced Nd:YAG lasers. Low-recast drilling of small holes (4-10 mil) in high-nickel alloy steel and high-edge-quality cutting of graphite:epoxy composites and other advanced composites are presented. The effect of wavelength, pulse format, beam intensity and other process parameters are discussed.Present-day Nd:YAG lasers are inadequate for carrying out precision drilling and cutting operations in advanced aerospace materials such as high-nickel alloy metals and graphite:epoxy composites. The high-brightness beams from next-generation solid-state lasers promise to overcome many of the deficiencies of present-day lasers, enabling improved small-hole drilling and improved low-heat-affected-zone cutting. This paper reviews examples of processing tests carried out with high-brightness 1.06 micron beams and 0.53 micron beams from advanced Nd:YAG lasers. Low-recast drilling of small holes (4-10 mil) in high-nickel alloy steel and high-edge-quality cutting of graphite:epoxy composites and other advanced composites are presented. The effect of wavelength, pulse format, beam intensity and other process parameters are discussed.

Levonorgestrel implants (Norplant) and medroxyprogesterone acetate injections (Depo-Provera) represent additional contraception options for adolescents. The purpose of this study was to examine prospectively clinical profiles among adolescents who chose one of the two long-term contraceptives compared with profiles among those who chose the combined oral contraceptive pill (OCP).Girls who needed contraception and did not require confidentiality were presented with a contraceptive menu consisting of Norplant (n = 58), Depo-Provera (n = 66), or OCP (n = 75). At baseline and follow-up visits over 6 months, patients were interviewed regarding gynecologic history, side effect symptoms, and satisfaction. The average age of subjects was 15.5 years (range 11 to 20 years); 66% were African-American and 34% white.Significantly more teens who chose Depo-Provera (73%) reported having used some method of birth control previously than those selecting either Norplant (30%) or OCP (26%). Adolescents who chose either Norplant (34%) or Depo-Provera (43%) were significantly more likely to have been pregnant previously than those choosing OCP (12%). Those selecting Depo-Provera were significantly more likely to report a history of genital infection with Chlamydia trachomatis (42%) than those in the other two contraceptive groups (22%). Prevalences of reported recent depression and fatigue before initiation of treatment were high, exceeding 35% across the three groups. A total of 105 and 40 adolescents were assessed at 3 and 6 months, respectively. At follow-up, more than 80% of OCP users maintained regular menstrual cycles, whereas over 80% of those choosing Norplant or Depo-Provera had disrupted cycles. Complaints of nausea and dizziness among Norplant users and fatigue among Depo-Provera and OCP users increased significantly between the baseline and follow-up visits. Reports of local reactions to the Norplant device were common but not clinically significant. Blood pressure readings, facial acne, and body mass index did not change over time in any treatment group. Subjects in the Norplant and Depo-Provera groups appreciated freedom from daily compliance to maintain contraceptive effectiveness and the "hidden" nature of the method. Appointment compliance at the end of 6 months was 78% for Depo-Provera, 40% for Norplant, and 46% for OCP.The implant and injection forms of contraception appear to be especially popular among girls with previous pregnancies or birth control use. The common occurrences of medical symptoms and sexually transmitted diseases before initiation of therapy underscore the importance of baseline evaluation. Norplant users may be warned about nausea and dizziness as well as minor local symptoms around the insertion site and unpredictable uterine bleeding patterns. Adolescent patients choosing Depo-Provera may expect amenorrhea by the end of 6 months of therapy along with possible fatigue. Early intervention may be needed with adolescents who choose Norplant or OCP to encourage better compliance with follow-up appointments.

Comparing sustained attention and inhibitory control among youth with sickle cell syndrome (SCS) and nondiseased sibling controls, this study found significant differences in multiple components of attention and inhibitory control as a function of chronological age. Older SCS youth were found to have increased attention and reflectivity. Although it has been argued that SCS youth without overt neurological impairments might evidence microvascular infarction, the present study, which employed commonly utilized neurocognitive and behavioral measures, does not lend support to the notion of generalized deficits in the absence of specific laboratory findings. Disease parameters including hemoglobin levels, days hospitalized, and emergency room visits were not significantly correlated with performance on any of the measures. Within the limitations of this particular study, results were interpreted to refute the notion of disease-related neurocognitive impairments for SCS youth. Further, the development of attentional skills for SCS youth is suggested to proceed similarly to that of normally developing youth.

From a health care point-of-view, the most needy adolescents in the United States are those who become incarcerated in the juvenile justice system. These youngsters have poor health care before incarceration is not much better. Their health problems range from the results of trauma to the consequences of sexual activity to severe psychological problems. Their health needs include: (1) prevention of health problems which contribute to behaviors for which youths are incarcerated; (2) comprehensive assessment and care; (3) continuity of care after discharge from the institutions; (4) comprehensive health education and health promotion; (5) professional, competent health care providers; (6) educated, sympathetic administrators and supervisory personnel; and (7) adequate financing of health services. Concerned health providers must become advocates for these adolescents and for their health care in correctional and political settings.

Adolescent pregnancy and its consequences continue as major sources of morbidity in the United States. A teenager who becomes a parent is at a significant disadvantage in becoming a contributing adult, both psychosocially and economically. The physician who cares for adolescents has the responsibility of helping parenting teens to find needed support so that they will be able to overcome this significant hurdle. Attention from public agencies has focused on increasing condom use as one approach to adolescent pregnancy prevention. The major advantage of using condoms is that they also prevent transmission of sexually transmitted diseases. Of note is that level of knowledge about condoms is not related to their use, and engaging in high-risk behaviors is related to a decreased likelihood of condom use. With rates of condom use estimated at less than 50%, rates of sexually transmitted disease remain high, as reported in recent surveys.Sexual activity among adolescents had increased in the US over the past 20 years. Surveys suggest that 14-44% of males and 7-30% of females under age 15 have had sexual intercourse. Risk factors for early sexual activity include low socioeconomic status, low future achievement orientation, and peer and media influence. Surveys indicate, however, that less than 50% of youths use condoms when having intercourse. Both pregnancy and sexually transmitted disease (STD) rates are therefore elevated in these populations in the US. 40% of female American adolescents are impregnated before turning 20 years old; approximately 75% of these pregnancies are unplanned. Of the more than 1 million annual adolescent pregnancies, 400,000 are aborted, 470,000 are born to term, and the rest result in spontaneous miscarriage. Only 5% of those ultimately born are turned over for adoption. The US public annual monetary cost of these unwanted and unplanned pregnancies is estimated to be $20 billion. Teen mothers usually do not finish their education, do not support themselves financially, have failed marriages, produce babies with relatively more health problems, and have more babies grouped close together by age. US adolescents and youths are simply not using contraception effectively. Condoms are especially appropriate and recommended within this age group due to the often sporadic nature and multiplicity of their sexual contacts, as well as the ability of condoms to reduce the risk of both pregnancy and STD transmission. Physicians need to teach and counsel their young clients, and advocate that they receive services targeted to their needs. Finally, any such interventions should be developed with the understanding that the level of knowledge about condoms is not related to their use, and that high- risk sex behavior is related to a decreased likelihood of condom use. Risk prevention efforts should reach young adolescents before they initiate and become accustomed to sexual risk-taking, and aim to change attitudes toward peer beliefs and behaviors; decrease perceived costs; and increase attitudes about the effectiveness of condoms in preventing STDs.

Treatment-related cognitive impairments have been reported for survivors of childhood leukemia following prophylactic central nervous system (CNS) treatment with craniospinal radiation. We examined the neurocognitive status of 46 children with acute lymphocytic leukemia (ALL) to assess the impact of a regimen consisting of systemic chemotherapy and prophylactic CNS chemotherapy. By comparing three groups of ALL children (i.e., patients whose diagnosis was recent, patients 1 year postdiagnosis currently receiving CNS prophylactic chemotherapy, and off-therapy patients who had been treated with chemotherapy for 3 years) and their healthy siblings on measures of sequential and simultaneous processing, we were able to examine the effects of CNS prophylactic and systemic chemotherapy at various points during treatment. Results indicate that the children who had received a 3-year course of chemotherapy (off-therapy patients) were more impaired on tasks involving right-hemisphere simultaneous processing than were sibling controls or ALL children whose diagnosis was recent and whose treatment had just begun. Age at diagnosis did not interact with the effects of chemotherapy. These findings support the need for continued evaluation of cognitive functioning in ALL, children receiving CNS prophylactic chemotherapy to identify potential harmful neurocognitive sequelae of treatment.

The influence of physiologic, psychologic, and cultural influences on human sexuality is reviewed. These factors are considered in the exploration of how adolescents express their sexuality and the consequences of that expression.

Increased plasma adrenalin (A) levels following arecoline in normal subjects and patients with multiple system atrophy (MSA) may result from nicotinic adrenal stimulation. Lack of this response in patients with pure autonomic failure (PAF) is consistent with peripheral sympathetic dysfunction. The mechanisms underlying diminished plasma corticotropin (ACTH) responses to arecoline may differ in patients with autonomic failure. Hypothalamic, cholinergic degeneration could prevent the response in MSA whereas patients with PAF do not manifest the normal increase in A which may be required to elicit an ACTH response. The appearance and exacerbation of tremor, vertigo, and pathological affect in the MSA group suggest that some central cholinergic receptors remain functional.

The Shy-Drager syndrome (SDS) is a form of progressive autonomic nervous system failure (PAF) with orthostatic hypotension and associated extrapyramidal involvement that is often mistaken for Parkinson disease. SDS includes olivopontocerebellar atrophy and striatonigral degeneration which is attended by PAF. Eight patients with SDS were studied on a 0.5-T superconducting system utilizing T1-weighted inversion recovery (IR) and T2-weighted spin-echo pulse sequences and also on a 1.5-T system using spin-echo sequences. With IR sequences, atrophy of the putamina was demonstrated in patients with SDS that is consistent with findings of neuronal loss in these nuclei reported on postmortem examinations. An abnormal decrease in signal intensity of the putamina, particularly along their lateral and posterior portions, was also detected, predominantly on T2-weighted sequences, and in three cases on T1-weighted spin-echo sequences. Abnormalities were detected on both imagers but were shown with greater clarity on the 1.5-T device. SDS is the first disease in which convincing basal ganglia changes have been shown in vivo exclusively by MR imaging.

A field test is performed to determine the upwelling flow from a 20-m deep air diffuser operating in Upper Bear Creek reservoir in northern Alabama. Dye is injected at a constant rate from a 6-m long diffuser pipe directly above the 12-m long air diffuser. Dye concentrations and velocities are measured in the flow-away current to estimate the total upwelling flow. The field estimate is compared to equations from the literature. The measured Upper Bear Creek diffuser upwelling flow is consistent with these equations for the normal air flow rate of 0.012 m3/sec. The dye and velocity measurements indicate an upwelling flow of 12 m3/sec and 10 m3/sec, respectively. A second test with an air flow rate of 0.024 m3/sec indicates an upwelling flow of 18 m3/sec from the dye dilution and 13 m3/sec from the velocities.

Tabulations are presented of the atomic form factor,F (α,Z), and the incoherent scattering function, S (x,Z), for values of x (=sin ϑ/2)/λ) from 0.005 A−1 to 109 A−1, for all elements A=1 to 100. These tables are constructed from available state‐of‐the‐art theoretical data, including the Pirenne formulas for Z=1, configuration‐into action results by Brown using Brown‐Fontana and Weiss correlated wavefunctions for Z=2 to 6 non‐relativistic Hartree‐Fock results by Cromer for Z=7 to 100 and a relativistic K‐shell analytic expression for F (x,Z) by Bethe Levinger for x≳10 A−1 for all elements Z=2 to 100. These tabulated values are graphically compared with available photon scatteringangular distributionmeasurements. Tables of coherent (Rayleigh) and incoherent (Compton) total scattering cross sections obtained by numerical integration over combinations of F 2(x,Z) with the Thomson formula and S (x,Z) with the Klum‐Nishina Formual, respectively, are presented for all elements Z=1 to 100, for photon energies 100 eV (λ=124 A) to 100 MeV (0.000124 A). The incoherent scattering cross sections also include the radiative and double‐Compton corrections as given by Mork. Similar tables are presented for the special cases of terminally‐bonded hydrogen and for the H2 molecule, interpolated and extrapolated from values calculated by Stewart et al., and by Bentley and Stewart using Kolos‐Roothaan wavefunctions.

This article describes the various hallucinogens with which adolescents may come in contact. Perspective is provided as to the importance of the various hallucinogens and to their effects on adolescent users.

The results of preliminary time-course studies on the uptake of radio-labelled alkaloid precursors, L-[methylene 14C]-tryptophan, [C-5 3H]-secologanin, [C-3 3H]-strictosidine, [Ar 3H]-strictosidine/vincoside and alkaloids, [C-8 3H]-quinine and-quinidine, by Cinchona ledgeriana root organs at various stages of the growth cycle are presented. Incorporation of the radio-label from [C-5 3H]-secologanin and [side chain 2 14C]-tryptamine into quinine and quinidine is also reported. Improved alkaloid yields obtained on feeding L-tryptophan have been shown to be dependent on the stage of the growth cycle at which feeding takes place.

INTRODUCTION A long-term study of the plant communit:es of Wisconsin, involving the examination of large numbers of stands of each major vegetation type, was begun in 1945. To date, prairie relics (Curtis & Green 1949), pine relics (McIntosh 1950), and upland hardwood forests (Curtis & McIntosh 1951) have been investigated. The present paper deals with a study of 116 stands of upland conifer-hardwood forests in northeastern Wisconsin, with emphasis on the relations of the various stands to each other and to their physical environment. Many persons contributed invaluable aid during the progress of the work. Dr. Grant Cottain directed much of the field work in 1950 and contributed stimulating advice throughout the study. Drs. Robert McIntosh, Max Partch, and Forest Stearns, Miss Margaret Gilbert, and Messrs. Orlin Anderson, William Randall, and Edward Terrell all helped in the collection of field data. Drs. F. D. Hole, F. T. Thwaites, and R. F. Bryson gave advice on problems of soils, geology, and meteorology respectively. To all these and to all others who helped in other ways, we extend our sincere appreciation. This work was supported in part by the Research Committee of the Graduate School of the University of Wisconsin from funds supplied by the Wisconsin Alumni Research Foundation.

Some ambiguity has been associated with the value of the degeneracy factor for the first acceptor level that is evident when zinc is diffused into silicon crystals. Both ½ and 2 have previously been reported. We obtain a confirmation of the latter figure by careful comparison of experimental data with theoretical relations. In addition, evidence is obtained which suggests that optical‐mode scattering may become dominant above 320°K. For this region, we present an equation for the Hall‐coefficient factor rp.

The seal on a metal-to-metal gasketed joint is effected by the imposition of bearing stresses, shearing stresses, or a combination of the two at the interface of the gasket and its mating seating surface. The required initial load to establish this seal for a given leak rate is greatly influenced by the gasket geometry and the type of sealing stress inherent to it. The retention of the seal under operating conditions is affected by the ability of the gasket to maintain contact with its mating surfaces through “springback” from the initial bolt-up deformations until the pressure loading is sufficient to take over. Theoretical investigations using the finite element method have been employed to determine suitable gasket geometry. Test data obtained from a full scale model are presented for comparison with the predicted values.

Detailed correlation of Hall Effect and resistivity data with electron statistics relations have been performed for experimentally determining the degeneracy ratio for the lower acceptor level of gold in germanium. Information on the density of gold in the germanium crystals is deduced through growing indentical crystals except that the dominant shallow impurity is a donor in one case and an acceptor in the other. A value for the degeneracy ratio of four is obtained. The Hall effect data is supported by neutron activation analysis data.

Fur ein neues glukosidisches Indolalkaloid ausAdina rubescens wird anhand instrumental-analytischer Untersuchungen die Struktur von 5-Oxostrictosidin vorgeschlagen.

Three canthin-6-one alkaloids, canthin-6-one, 5-methoxycanthin-6-one and the novel alkaloid 1-hydroxy-11-methoxycanthin-6-one have been isolated from the root bark of BRUCEA ANTIDYSENTERICA.