Sum frequency generation as a proxy for ellipsometry: Not just a phase.

Infrared refractive indices of organic materials are typically resolved through IR ellipsometry. This technique takes advantage of optical interference effects to solve the optical constants. These are the same effects that complicate the analysis of coherent spectroscopy experiments on thin films. Vibrational sum frequency generation is an interface-specific coherent spectroscopy that requires spectral modeling to account for optical interference effects to uncover interfacial molecular responses. Here, we explore the possibility of leveraging incident beam geometries and sample thicknesses to simultaneously obtain the molecular responses and refractive indices. Globally fitting a higher number of spectra with a single set of refractive indices increases the fidelity of the fitted parameters. Finally, we test our method on samples with a range of thicknesses and compare the results to those obtained by IR ellipsometry.

Structure of a guinea pig common precursor to a MSEL-type neurophysin and copeptin.

From guinea pig posterior pituitaries, a MSEL-type neurophysin (neurophysin containing methionine-2, serine-3, glutamic acid-6 and leucine-7), a glycopeptide referred to as copeptin and their common precursor have been purified to homogeneity and sequenced. The performed acid-oxidized precursor, subjected to trypsin hydrolysis, has given 9 peptides, 6 of which (T1-T6) identical to those given by oxidized MSEL-neurophysin except that T6 has an additional C-terminal arginine residue when compared to its homologue. The other 3 tryptic peptides (T7-T9) are identical to those given by copeptin. The 132-residue precursor therefore comprises a MSEL-type neurophysin (93 residues) and copeptin (38 residues) linked by an arginine residue. The molar proportion of this bound form compared with the free polypeptides is approximately 20%. It is believed that this precursor is a part of the vasopressin-MSEL-neurophysin-copeptin precursor incompletely processed during the transport from hypothalamus to neurohypophysis.

Emergence and preservation of a chronically sick building.

STUDY OBJECTIVE: To investigate the merits of case studies as complementary methodological approaches in the study of the sick building syndrome. SETTING AND PARTICIPANTS: A Swedish office building with longstanding health problems, and its inhabitants. DESIGN: This paper is a case study based both on historical and present, quantitative as well as qualitative, documentary material, produced over the years by distinct parties, and on semi-structured interviews. RESULTS: Long drawn conflictive processes within the building were identified. It was revealed that the organisation for dealing with environmental problems was split, and ineffective with poor patterns of communication. It was suggested that this generated a situation of chronic stress leading to the persistence of symptoms. CONCLUSIONS: By their capacity to identify internal processes within building contexts, case study methodology can contribute to a better understanding and management of sick building syndrome. The results of this study suggest that psychosocial factors, among them organisational structures and communication patterns, should be given close attention.

The sick building syndrome: a diagnostic dilemma.

Sick building syndrome (SBS) is usually defined as an increased occurrence of non-specific symptoms among populations in determined buildings. This definition differs from those of other medical syndromes in that it refers to a system (a building inclusive of its population) rather than to a clinical state in a single individual. Such a definition should make the term SBS impossible to use as a diagnosis applied to individual persons. In spite of this, it is often used in this way, and the aim of the article is to discuss problems with this practice. It is a case study based on an office building with long-standing building-related health problems. Information concerning the building and its inhabitants comes from a large number of separate documentary sources. The study demonstrates that the diagnostic use of SBS suffers from serious weaknesses. It is proposed that such diagnostics could even have a normative force serving to maintain and reinforce building-related, non-specific health problems. It is therefore suggested that the term sick building syndrome should be abandoned.

Results from a community intervention project in the Nicaraguan mining community El Limon. An overview.

The first steps of a community involvement health project using the principles of community diagnosis and popular participation were carried out in a small Nicaraguan mining village during the second half of the 1980s. Using existing archives and obtaining new information aided by local organizations, priorities could be established for health and safety surveillance within the mining company, as well as for further investigations concerning what seemed to be dominant health problems in the community: serious accidents among the economically active population and diarrhoea and respiratory tract infections among children, as well as infections, and other health indicators of malnutrition. Workers also presented chronic simple bronchitis, ventilatory obstructive disturbance and hearing loss that were strongly associated with working conditions. These results helped to direct health priorities and educational activities at the local level with both the general and working population. The wide experience gained from this study has encouraged us to strengthen the link between research and action and in performing studies in close cooperation with local organizations.

Language differences in verbal short-term memory do not exclusively originate in the process of subvocal rehearsal.

Language differences in verbal short-term memory were investigated in two experiments. In Experiment 1, bilinguals with high competence in English and French and monolingual English adults with extremely limited knowledge of French were assessed on their serial recall of words and nonwords in both languages. In all cases recall accuracy was superior in the language with which individuals were most familiar, a first-language advantage that remained when variation due to differential rates of articulation in the two languages was taken into account. In Experiment 2, bilinguals recalled lists of English and French words with and without concurrent articulatory suppression. First-language superiority persisted under suppression, suggesting that the language differences in recall accuracy were not attributable to slower rates of subvocal rehearsal in the less familiar language. The findings indicate that language-specific differences in verbal short-term memory do not exclusively originate in the subvocal rehearsal process. It is suggested that one source of language-specific variation might relate to the use of long-term knowledge to support short-term memory performance.

Allergic alveolitis in a school environment.

BACKGROUND: A considerable fraction of newly constructed buildings have indoor air problems associated with health effects, usually of the nonspecific sick building syndrome variety. Specific health effects such as asthma, rhinitis, and allergic alveolitis can also occur. CASE: On 1 September 1988 a school teacher showed symptoms of an acute respiratory illness, which was first interpreted as pulmonary embolism and then later as atypical sarcoidosis. The illness slowly progressed over six years, at which time the diagnosis was revised to chronic allergic alveolitis, related to her school environment. The school had had indoor-air quality problems off and on for several years. CONCLUSIONS: The case illustrates the difficulties of diagnosing cases of chronic allergic alveolitis, especially when it appears in environments where it is not generally encountered. It also raises questions regarding a possible relation between environments associated with the sick building syndrome and the occurrence of building-associated illnesses.

Pests, peasants, and pesticides on the Northern Nicaraguan Pacific Plain.

With the aim of exploring possible reasons for dangerous work practices among small-scale farmers in the Pacific plain of Nicaragua, a qualitative study was performed. Four focus groups were involved. The information gathered was analyzed with an emphasis on the farmers' relationships to and perspectives on their crops, the economy, pests, and pesticide hazards. Factors that had been anticipated, such as poverty, inadequacy of protective devices, and environmental factors, were found to lead to dangerous work practices. Cultural factors also affected the farmers' attitudes in ways that favored hazardous work procedures. This finding, which had not been anticipated, has important practical implications. It suggests that, to be effective, education and training courses on occupational health should assure that their design, language, materials, and execution are culturally relevant and appropriate.

Experiences from long-term research cooperation between Costa Rican, Nicaraguan, and Swedish institutions.

This paper summarizes experiences from long-term ongoing cooperation between Swedish research institutions and institutions at the National Universities in Nicaragua and Costa Rica. 24 researchers and teachers from the Central American institutions and ten Swedish research students have been trained. In addition to three full doctoral and three licentiate (two-year PhD program) theses, the two programs have so far published 15 articles in English-language, international, refereed journals and about three times as many abstracts for conferences in more than ten countries. A "sandwich" model for training is recommended, where the southern researchers come to the wealthier partner for collaborative analyses and write-ups of the publications, while spending 50-75% of their time in their home countries for data collection. Such collaboration should be planned for a time span of at least eight years and include substantial numbers of researchers and students. Means to minimize the risk of brain drain are suggested. The collaboration has been important for the globalization of the research cultures at the participating institutions and has trained international experts.

Building-related health problems: reflections on different symptom prevalence among pupils and teachers.

The occurrence of non-specific symptoms among populations in modern buildings is common in the northern parts of the world, and is often called the Sick Building Syndrome. Many factors have been shown to be associated with the prevalence of such symptoms. Based on a case study of a primary school in subarctic Sweden, the complicated nature of building-related, non-specific symptoms is reviewed. Preventive and corrective actions in cases of sick buildings often fail. It is suggested that failures of such actions might depend on their predominant origin in biomedical models. The study therefore proposes that the combined and simultaneous use of biomedical and psychosocial models should be tried in the management of building-related health problems.

[Sick building syndrome should be treated more from a reasonable than an evidence-based point of view]. / Sjuka hus-syndromet får behandlas mer utifrån rimlighet än evidens.

During the past decades, several non-specific syndromes have gradually appeared and eventually been given generic denominations such as "diseases of modern life". One of these is the so called Sick Building Syndrome (SBS), which consists of various combinations of common, non-specific symptoms as well as an absence of signs demonstrable by laboratory tests and other medical examinations or means. The lack of demonstrable biological correlates together with vague etiologic attributions make it unusually problematic to study, resulting in the production of a general, non-specific and sometimes contradictory fund of knowledge. This often transforms instances of SBS to theaters of conflict people by parties with divergent interests. Technical/scientific expertise can provide general advice but not unambiguously contribute to the resolution of the conflicts.

[Qualitative research methods in clinical practice]. / Kvalitativa forskningsmetoder i klinisk medicinsk praxis.

Evidence-based medicine (EBM) corresponds to the physician's ambition to integrate his/her experience with the best current scientific knowledge, applying this integrated proficiency to clinical problems. The concept of EBM has become widely accepted and given rise to a global network usually emphasizing the randomized clinical trial (RCT) as the most important scientific method. However, clinical situations are very complex. To a greater or less extent they are all composed of diverse factors, ranging from bio-medical ones to inter-subjective relations, values and beliefs. In addition to RCT and other quantitative procedures, qualitative scientific methods could be used to explore complex clinical problems. Clinical problems always deserve to be addressed from various perspectives. Unfortunately, RCT has acquired such a dominant position as to give the impression that it is the sole preferred method within the EBM framework. Based on three examples, the present article claims that it is the questions asked by an investigation that should determine one's choice of methods, not the reverse. Consequently, we argue that it is important to remember that RCT is just one out of several potential scientific methods. The respective utility of any one method depends on the clinical issue at hand.

A compact, versatile low-energy electron beam ion source.

A new compact Electron Beam Ion Source, the Dresden EBIT-LE, is introduced as an ion source working at low electron beam energies. The EBIT-LE operates at an electron energy ranging from 100 eV to some keV and can easily be modified to an EBIT also working at higher electron beam energies of up to 15 keV. We show that, depending on the electron beam energy, electron beam currents from a few mA in the low-energy regime up to about 40 mA in the high-energy regime are possible. Technical solutions as well as first experimental results of the EBIT-LE are presented. In ion extraction experiments, a stable production of low and intermediate charged ions at electron beam energies below 2 keV is demonstrated. Furthermore, X-ray spectroscopy measurements confirm the possibility of using the machine as a source of X-rays from ions excited at low electron energies.

Liquid metal alloy ion source based metal ion injection into a room-temperature electron beam ion source.

We have carried out a series of measurements demonstrating the feasibility of using the Dresden electron beam ion source (EBIS)-A, a table-top sized, permanent magnet technology based electron beam ion source, as a charge breeder. Low charged gold ions from an AuGe liquid metal alloy ion source were injected into the EBIS and re-extracted as highly charged ions, thereby producing charge states as high as Au(60 +). The setup, the charge breeding technique, breeding efficiencies as well as acceptance and emittance studies are presented.

Demonstration of charge breeding in a compact room temperature electron beam ion trap.

For the first time, a small room-temperature electron beam ion trap (EBIT), operated with permanent magnets, was successfully used for charge breeding experiments. The relatively low magnetic field of this EBIT does not contribute to the capture of the ions; single-charged ions are only caught by the space charge potential of the electron beam. An over-barrier injection method was used to fill the EBIT's electrostatic trap with externally produced, single-charged potassium ions. Charge states as high as K(19+) were reached after about a 3 s breeding time. The capture and breeding efficiencies up to 0.016(4)% for K(17+) have been measured.

Status report of the Dresden EBIS/EBIT developments.

We give an overview about latest developments and measurements with the Dresden electron beam ion source family as compact and economically working table-top sources of highly charged ions. The ion sources are potential tools for various applications such as for use in combination with accelerators in medical particle therapy, as charge breeder or ion trap injector, as ion sources for a new generation of focused ion beam devices and for applications together with time-of-flight secondary mass spectrometers.