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2.
Oncogene ; 35(33): 4368-78, 2016 08 18.
Article in English | MEDLINE | ID: mdl-26804170

ABSTRACT

Bruton's tyrosine kinase (BTK) is essential for B-cell proliferation/differentiation and it is generally believed that its expression and function are limited to bone marrow-derived cells. Here, we report the identification and characterization of p65BTK, a novel isoform abundantly expressed in colon carcinoma cell lines and tumour tissue samples. p65BTK protein is expressed, through heterogeneous nuclear ribonucleoprotein K (hnRNPK)-dependent and internal ribosome entry site-driven translation, from a transcript containing an alternative first exon in the 5'-untranslated region, and is post-transcriptionally regulated, via hnRNPK, by the mitogen-activated protein kinase (MAPK) pathway. p65BTK is endowed with strong transforming activity that depends on active signal-regulated protein kinases-1/2 (ERK1/2) and its inhibition abolishes RAS transforming activity. Accordingly, p65BTK overexpression in colon cancer tissues correlates with ERK1/2 activation. Moreover, p65BTK inhibition affects growth and survival of colon cancer cells. Our data reveal that BTK, via p65BTK expression, is a novel and powerful oncogene acting downstream of the RAS/MAPK pathway and suggest that its targeting may be a promising therapeutic approach.


Subject(s)
Cell Transformation, Neoplastic , Colonic Neoplasms/pathology , Protein-Tyrosine Kinases/physiology , ras Proteins/physiology , 5' Untranslated Regions/physiology , Agammaglobulinaemia Tyrosine Kinase , Cell Line, Tumor , Colonic Neoplasms/enzymology , Heterogeneous-Nuclear Ribonucleoprotein K/physiology , Humans , MAP Kinase Signaling System/physiology , Protein Isoforms/genetics , Protein Isoforms/physiology , Protein-Tyrosine Kinases/analysis , Protein-Tyrosine Kinases/genetics
3.
Rev Sci Instrum ; 86(5): 056108, 2015 May.
Article in English | MEDLINE | ID: mdl-26026569

ABSTRACT

A prototype analyzer for the detection of hydrogen sulfide (H2S), based on cavity ring-down spectroscopy, is described. The device exploits, whenever possible, optical fibers, in order to simplify the alignment and to improve the stability. A trade-off between low detection level and simplicity has been pursued. The experimental results obtained during tests on different kinds of H2S samples are shown.

4.
Opt Express ; 22(23): 28222-31, 2014 Nov 17.
Article in English | MEDLINE | ID: mdl-25402062

ABSTRACT

A compact widely-tunable fiber-coupled sensor for trace gas detection of hydrogen sulfide (H2S) in the mid infrared is reported. The sensor is based on an external-cavity quantum cascade laser (EC-QCL) tunable between 7.6 and 8.3 µm wavelengths coupled into a single-mode hollow-core waveguide. Quartz-enhanced photoacoustic spectroscopy has been selected as detecting technique. The fiber coupling system converts the astigmatic beam exiting the laser into a TEM(00) mode. During a full laser scan, we observed no misalignment between the optical beam and the tuning fork, thus making our system applicable for multi-gas or broad absorber detections. The sensor has been tested on N2:H2S gas mixtures. The minimum detectable H2S concentration is 450 ppb in ~3 s integration time, which is the best value till now reported in literature for H2S optical sensors.


Subject(s)
Environmental Monitoring/instrumentation , Gases/analysis , Lasers, Semiconductor , Quartz , Spectrum Analysis/instrumentation , Equipment Design
5.
New Microbes New Infect ; 2(4): 136-7, 2014 Jul.
Article in English | MEDLINE | ID: mdl-25356361

ABSTRACT

Coxiella burnetii Dog Utad, with a 2 008 938 bp genome is a strain isolated from a parturient dog responsible for a human familial outbreak of acute Q fever in Nova Scotia, Canada. Its genotype, determined by multispacer typing, is 21; the only one found in Canada that includes Q212, which causes endocarditis. Only 107 single nucleotide polymorphisms and 16 INDELs differed from Q212, suggesting a recent clonal radiation.

6.
Opt Lett ; 39(16): 4843-6, 2014 Aug 15.
Article in English | MEDLINE | ID: mdl-25121889

ABSTRACT

Mid-infrared digital holography based on CO2 lasers has proven to be a powerful coherent imaging technique due to reduced sensitivity to mechanical vibrations, increased field of view, high optical power, and possible vision through scattering media, e.g., smoke. Here we demonstrate a similar and more compact holographic system based on an external cavity quantum cascade laser emitting at 8 µm. Such a setup, which includes a highly sensitive microbolometric camera, allows the acquisition of speckle holograms of scattering objects, which can be processed in real time. In addition, by exploiting the broad laser tunability, we can acquire holograms at different wavelengths, from which we extract phase images not subjected to phase wrapping, at synthetic wavelengths ranging from hundreds of micrometers to several millimeters.

7.
Behav Brain Res ; 251: 75-84, 2013 Aug 15.
Article in English | MEDLINE | ID: mdl-23327738

ABSTRACT

Autism is a pervasive disorder characterized by a complex symptomatology, based principally on social dysfunction. The disorder has a highly complex, largely genetic etiology, involving an impressive variety of genes, the precise contributions of which still remain to be determined. For this reason, a reductionist approach to the study of autism has been proposed, employing monogenic animal models of social dysfunction, either by targeting a candidate gene, or by mimicking a single-gene disorder characterized by autistic symptoms. In the present review, we discuss this monogenic approach by comparing examples of each strategy: the mu opioid receptor knock-out (KO) mouse line, which targets the opioid system (known to be involved in the control of social behaviors); and the Fmr1-KO mouse, a model for Fragile X syndrome (a neurodevelopmental syndrome that includes autistic symptoms). The autistic-relevant behavioral phenotypes of the mu-opioid and Fmr1-KO mouse lines are described here, summarizing previous work by our research group and others, but also providing novel experimental evidence. Relevant factors influencing the validity of the two models, such as sex differences and age at testing, are also addressed, permitting an extensive evaluation of the advantages and limits of monogenic mouse models for autism.


Subject(s)
Autistic Disorder/genetics , Behavior, Animal/physiology , Disease Models, Animal , Social Behavior , Animals , Fragile X Mental Retardation Protein/genetics , Fragile X Syndrome/genetics , Mice
8.
Eur J Clin Microbiol Infect Dis ; 32(3): 361-8, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23052984

ABSTRACT

The link between fetal morbidity and Q fever and the necessity of long-term antibiotics for Coxiella burnetii infection during pregnancy have been recently questioned in the Netherlands, where the clone responsible for the Q fever outbreak harbors the QpH1 plasmid. In this context, we assessed pregnancy outcomes according to antibiotic administration in a new series and compared the plasmid type between isolates associated with abortion and other clinical isolates to determine if there is a link between genotype and abortion in humans. All French patients who received a diagnosis of Q fever during pregnancy at the French National Referral Centre for Q Fever from 2006 through July 2011 were included. On the other hand, the plasmid types of 160 clinical isolates, including seven isolates from patients who experienced an abortion, were compared. The differences between the QpDV and QpH1 plasmid sequences were analyzed. Acute Q fever was a cause of fetal morbidity, and the absence of long-term cotrimoxazole therapy was associated with fetal death (p < 0.0001). Genotypic analysis showed that the QpDV plasmid was more frequent in isolates associated with abortion (p = 0.03). A comparison of the plasmid sequences revealed that four QpDV proteins had no direct counterparts in QpH1, with two whose functions were not present in QpH1. The different obstetrical morbidity of C. burnetii relative to different geographical areas could be related to strain specificity, possibly based on differences in plasmid sequences, or to a failure of public health authorities to detect early miscarriages.


Subject(s)
Abortion, Septic/microbiology , Coxiella burnetii/genetics , Plasmids/analysis , Pregnancy Complications, Infectious/epidemiology , Pregnancy Complications, Infectious/prevention & control , Q Fever/epidemiology , Q Fever/prevention & control , Adult , Anti-Bacterial Agents/therapeutic use , Coxiella burnetii/classification , Coxiella burnetii/isolation & purification , Coxiella burnetii/pathogenicity , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Female , Fetal Mortality , France/epidemiology , Genotype , Humans , Pregnancy , Pregnancy Complications, Infectious/microbiology , Q Fever/microbiology , Sequence Analysis, DNA , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Virulence
9.
Transl Psychiatry ; 2: e155, 2012 Aug 28.
Article in English | MEDLINE | ID: mdl-22929597

ABSTRACT

Social anhedonia, or the diminished capacity to experience pleasure and reward from social affiliation, is a major symptom of different psychiatric disorders, including some forms of infantile autism and schizophrenia spectrum disorders. The brain opioid hypothesis of social attachment is a promising model for achieving insights into how neurobiological and developmental factors contribute to the regulation of social reward. In this study, genetic knocking-out and naltrexone (NTRX) treatment during the first 4 days of life were used to disrupt opioid neurotransmission in mouse pups and their attachment relationships with the mother. Both permanent (genetic) and transient (pharmacological) manipulations of opioid neurotransmission exerted long-term effects on social affiliation. When juveniles, both µ-opioid receptor knockout mice and NTRX-treated pups showed reduced interest in peers and no preference for socially rewarding environment. These results demonstrate that sociability in juvenile mice is highly dependent on the establishment during infancy of a positive affective relationship with their mothers and that opioid neurotransmission has a major role in the regulation of social hedonic capacity. If the validity of this animal model will be confirmed by future research, translational studies focusing on the interaction between early experience and opioid neurotransmission could provide useful insights for identifying endophenotypes of human psychiatric disorders associated with social anhedonia.


Subject(s)
Anhedonia/physiology , Behavior, Animal/physiology , Disease Models, Animal , Naltrexone/adverse effects , Object Attachment , Reactive Attachment Disorder/chemically induced , Receptors, Opioid, mu/genetics , Synaptic Transmission/genetics , Analysis of Variance , Anhedonia/drug effects , Animals , Behavior, Animal/drug effects , Mice , Mice, Knockout , Reactive Attachment Disorder/genetics , Receptors, Opioid, mu/drug effects , Receptors, Opioid, mu/physiology , Synaptic Transmission/drug effects , Synaptic Transmission/physiology
10.
Behav Brain Res ; 229(2): 333-9, 2012 Apr 15.
Article in English | MEDLINE | ID: mdl-22289198

ABSTRACT

The impact of stress is widely recognized in the etiology of multiple disorders. In particular, psychological stress may increase the risk of cardiovascular, metabolic, immune, and mood disorders. Several genes are considered potential candidates to account for the deleterious consequences of stress and recent data point to role of Vgf. VGF mRNA is abundantly expressed in the hypothalamus, where it has been involved in metabolism and energy homeostasis; more recently a link between VGF-derived peptides and mood disorders has been highlighted. The following experiments were performed to address the contribution of the VGF-system to stress induced changes in mice: the distribution of VGF immuno-reactivity in hypothalamic nuclei and its modulation by social stress; the role of VGF-derived peptide TLQP-21 in plasma catecholamine release induced by acute restraint stress (RS); the efficacy of chronic TLQP-21 in a mouse model of chronic subordination stress (CSS). VGF fibers were found in high density in arcuate, dorsomedial, and suprachiasmatic and, at lower density, in lateral, paraventricular, and ventromedial hypothalamic nuclei. Central administration of either 2 or 4 mM TLQP-21 acutely altered the biphasic serum epinephrine release and decreased norepinephrine serum levels in response to RS. Finally, 28-day of 40 µg/day TLQP-21 treatment increased CSS-induced social avoidance of an unfamiliar conspecific. Overall these data support a role for TLQP-21 in stress responses providing a promising starting point to further elucidate its role as a player in stress-related human pathologies.


Subject(s)
Hypothalamus/metabolism , Neuropeptides/metabolism , Peptide Fragments/pharmacology , Peptide Fragments/therapeutic use , Stress, Psychological/drug therapy , Stress, Psychological/metabolism , Animals , Avoidance Learning/drug effects , Catecholamines/blood , Disease Models, Animal , Hypothalamus/drug effects , Infusions, Subcutaneous , Injections, Intraventricular , Male , Mice , Mice, Inbred ICR , Motor Activity/drug effects , Nerve Growth Factors , Peptide Fragments/administration & dosage , Social Behavior , Stress, Psychological/blood
11.
Genes Brain Behav ; 9(1): 26-32, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19740091

ABSTRACT

Mice lacking the serotonin receptor 1A (Htr1a knockout, Htr1a(KO)) show increased innate and conditioned anxiety. This phenotype depends on functional receptor activity during the third through fifth weeks of life and thus appears to be the result of long-term changes in brain function as a consequence of an early deficit in serotonin signaling. To evaluate whether this phenotype can be influenced by early environmental factors, we subjected Htr1a knockout mice to postnatal handling, a procedure known to reduce anxiety-like behavior and stress responses in adulthood. Offspring of heterozygous Htr1a knockout mice were separated from their mother and exposed 15 min each day from postnatal day 1 (PD1) to PD14 to clean bedding. Control animals were left undisturbed. Maternal behavior was observed during the first 13 days of life. Adult male offspring were tested in the open field, social approach and resident-intruder tests and assessed for corticosterone response to restraint stress. Knockout mice showed increased anxiety in the open field and in the social approach test as well as an enhanced corticosterone response to stress. However, while no effect of postnatal handling was seen in wild-type mice, handling reduced anxiety-like behavior in the social interaction test and the corticosterone response to stress in knockout mice. These findings extend the anxiety phenotype of Htr1a(KO) mice to include social anxiety and demonstrate that this phenotype can be moderated by early environmental factors.


Subject(s)
Animals, Newborn/metabolism , Animals, Newborn/psychology , Anxiety/metabolism , Handling, Psychological , Receptor, Serotonin, 5-HT1A/deficiency , Social Behavior , Animals , Animals, Newborn/blood , Corticosterone/blood , Female , Male , Maternal Behavior , Maternal Deprivation , Mice , Mice, Knockout , Restraint, Physical , Serotonin/metabolism , Stress, Physiological , Ultrasonics , Vocalization, Animal
12.
Eat Weight Disord ; 13(3): e55-60, 2008 Sep.
Article in English | MEDLINE | ID: mdl-19011365

ABSTRACT

The aim of the study was to assess the effects of chronic olanzapine (Ola) administration on feeding behavior. Although atypical antipsychotics (AAPs) have greatly improved the management of schizophrenia and extrapyramidal symptoms, substantial bodies of literature point out that most of these agents are highly related to a major risk of metabolic drawbacks, leading to dyslipidemia and obesity. Among these compounds, Ola is one of the more weight gain-inducing AAPs. In the present study, we analyzed the Behavioral Satiety Sequence (BSS) in female mice given a palatable diet (wet mash) and chronically administered Ola (0.75, 1.5, 3 mg/kg per os) for 36 days. The results showed that administration of the highest dose of Ola postponed the onset of satiation, as suggested by the rightward shift of the BSS. This effect was confirmed by an increase in the actual food intake by the Ola (3 mg/kg) mice. These results suggest that one of the possible mechanisms involved in AAPinduced weight gain is alteration of the hunger-satiety regulation in female mice. These findings are consistent with the hypothesis that enhanced food intake and diminished central sensitivity to satiation signaling may cooperate in promoting weight gain and metabolic dysregulation in rodents and patients taking antipsychotic medications.


Subject(s)
Antipsychotic Agents/adverse effects , Benzodiazepines/adverse effects , Eating/drug effects , Feeding Behavior/physiology , Satiety Response/drug effects , Weight Gain/drug effects , Administration, Oral , Analysis of Variance , Animals , Antipsychotic Agents/administration & dosage , Antipsychotic Agents/pharmacology , Benzodiazepines/administration & dosage , Benzodiazepines/pharmacology , Dose-Response Relationship, Drug , Female , Mice , Olanzapine , Time Factors , Weight Gain/physiology
13.
Psychoneuroendocrinology ; 33(4): 462-70, 2008 May.
Article in English | MEDLINE | ID: mdl-18308478

ABSTRACT

BACKGROUND: Early adverse experiences are preeminent factors for the development of affective disorders. In the present study, we analyzed the effects of different postnatal manipulations applied either on the mother or on the offspring in mice. Maternal behavior and adrenocortical activity of both mothers and offspring at the end of postnatal stress and at adulthood were considered. METHODS: From postnatal day (PND) 1 to 14 mice underwent 15min of: (a) brief (15min) pups' exposure to clean bedding (CB: clean bedding), (b) mothers' exposure to the odor of a novel male (SM: stressed mother) or (c) mothers' exposure to a clean cage (CSM: control stressed mother), and (d) standard rearing (N-H: non-handled). The behavior of mouse dams during and after stress sessions was analyzed. Serum corticosterone of mothers and pups at the end of the stress session and 30min after reunion was assessed on PND 14. Moreover, anxiety levels and HPA-axis inhibitory feedback in response to dexamethasone administration were evaluated in adult male offspring. RESULTS: Overall, during the 14 days of treatment CB mothers when reunited with their pups showed higher maternal behavior than other dams. After the last stress (PND 14) SM and CSM maternal corticosterone levels increased as well as those of CB pups. While 30min of mother-infant interaction restored baseline corticosterone levels in SM and CSM mothers and in CB pups, SM and CSM offspring showed a decrease of corticosterone under baseline levels. At adulthood, SM and CSM males did not show the suppressive hormonal response to dexamethasone treatment. Moreover, adult CB and SM male mice displayed decreased anxiety in the open field. CONCLUSIONS: Maternal psychosocial stress during lactation seems to permanently affect the offspring's HPA functioning. These effects may be dissociated from the behavioral response as suggested by the decrease of anxiety in SM and CB adult mice.


Subject(s)
Animals, Newborn/blood , Corticosterone/blood , Hypothalamo-Hypophyseal System/growth & development , Maternal Behavior/psychology , Pituitary-Adrenal System/growth & development , Stress, Psychological/psychology , Adrenal Cortex Hormones/blood , Age Factors , Animals , Dexamethasone/pharmacology , Female , Glucocorticoids/pharmacology , Hypothalamo-Hypophyseal System/metabolism , Male , Maternal Deprivation , Mice , Pituitary-Adrenal System/metabolism , Social Environment , Stimulation, Chemical
14.
Proc Natl Acad Sci U S A ; 103(39): 14584-9, 2006 Sep 26.
Article in English | MEDLINE | ID: mdl-16983076

ABSTRACT

The vgf gene has been identified as an energy homeostasis regulator. Vgf encodes a 617-aa precursor protein that is processed to yield an incompletely characterized panel of neuropeptides. Until now, it was an unproved assumption that VGF-derived peptides could regulate metabolism. Here, a VGF peptide designated TLQP-21 was identified in rat brain extracts by means of immunoprecipitation, microcapillary liquid chromatography-tandem MS, and database searching algorithms. Chronic intracerebroventricular (i.c.v.) injection of TLQP-21 (15 mug/day for 14 days) increased resting energy expenditure (EE) and rectal temperature in mice. These effects were paralleled by increased epinephrine and up-regulation of brown adipose tissue beta2-AR (beta2 adrenergic receptor) and white adipose tissue (WAT) PPAR-delta (peroxisome proliferator-activated receptor delta), beta3-AR, and UCP1 (uncoupling protein 1) mRNAs and were independent of locomotor activity and thyroid hormones. Hypothalamic gene expression of orexigenic and anorexigenic neuropeptides was unchanged. Furthermore, in mice that were fed a high-fat diet for 14 days, TLQP-21 prevented the increase in body and WAT weight as well as hormonal changes that are associated with a high-fat regimen. Biochemical and molecular analyses suggest that TLQP-21 exerts its effects by stimulating autonomic activation of adrenal medulla and adipose tissues. In conclusion, we present here the identification in the CNS of a previously uncharacterized VGF-derived peptide and prove that its chronic i.c.v. infusion effected an increase in EE and limited the early phase of diet-induced obesity.


Subject(s)
Diet/adverse effects , Energy Metabolism , Neuropeptides/metabolism , Obesity/chemically induced , Peptides/metabolism , Adipose Tissue, Brown/metabolism , Animals , Blood Glucose , Ghrelin , Glucose Tolerance Test , Ion Channels/genetics , Leptin/blood , Male , Mice , Mitochondrial Proteins/genetics , Nerve Growth Factors , Neuropeptides/chemistry , PPAR gamma/genetics , Peptide Hormones/blood , Peptides/chemistry , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Receptors, Adrenergic, beta/genetics , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Triglycerides/blood , Uncoupling Protein 1 , Up-Regulation/genetics
15.
Neuroscience ; 142(3): 823-32, 2006 Oct 27.
Article in English | MEDLINE | ID: mdl-16890369

ABSTRACT

The role of voltage-gated Ca(2+) (Ca(V)) channels in pain mechanisms has been the object of intense investigation using pharmacological approaches and, more recently, using mutant mouse models lacking the Ca(V)alpha(l) pore-forming subunit of N-, R- and T-type channels. The role of P/Q-type channels in nociception and pain transmission has been investigated by pharmacological approaches but remains to be fully elucidated. To address this issue, we have analyzed pain-related behavioral responses of null mutant mice for the Ca(V)2.1alpha(1) subunit of P/Q-type channels. Homozygous null mutant Ca(V)2.1alpha(1)-/- mice developed dystonia at 10-12 days after birth and did not survive past weaning. Tested at ages where motor deficit was either absent or very mild, Ca(V)2.1alpha(1)-/- mice showed reduced tail withdrawal latencies in the tail-flick test and reduced abdominal writhes in the acetic acid writhing test. Adult heterozygous Ca(V)2.1alpha(1)+/- mice did not show motor deficits in the rotarod and activity cage tests and did not show alterations in pain responses in the tail-flick test and the acetic acid writhing test. Strikingly, they showed a reduced licking response during the second phase of formalin-induced inflammatory pain and a reduced mechanical allodynia in the chronic constriction injury model of neuropathic pain. Our findings show that P/Q-type channels play an antinociceptive role in sensitivity to non-injurious noxious thermal stimuli and a pronociceptive role in inflammatory and neuropathic pain states, pointing to an important role of Ca(V)2.1 channels in central sensitization.


Subject(s)
Calcium Channels, N-Type/deficiency , Pain Threshold/physiology , Pain/genetics , Psychomotor Performance/physiology , Analysis of Variance , Animals , Animals, Newborn , Behavior, Animal , Female , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Motor Activity/genetics , Pain Measurement/methods , Protein Subunits/genetics , Reaction Time/genetics , Time Factors
16.
Psychoneuroendocrinology ; 31(5): 623-33, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16616814

ABSTRACT

Stress has been associated with changes in eating behaviour and food preferences. Moreover, psychosocial and socio-economical challenges have been related with neuroendocrine-autonomic dysregulation followed by visceral obesity and associated risk factors for disease. In the current study, we provide a model of body weight development, food intake, energy expenditure of subordinate and dominant mice under psychosocial stress either in the presence of a standard diet or of a high palatable diet. When only standard chow was available stressed animals consumed more food in comparison to the control counterpart. Moreover, subordinate mice, at the end of the stress period were heavier in comparison to dominant animals. This last result was due to a decrease in the caloric efficiency of dominant animals in comparison to subordinates. Confirming this, the results of the experiment 2 showed that dominant mice significantly increase their energy expenditure at the end of the chronic psychosocial stress procedure in comparison to subordinate mice, as measured by indirect calorimetry. When a palatable high fat diet was available subordinate animals became heavier in comparison with both dominant and control animals. No differences in the caloric intake were found between groups. Subordinate mice ingested more calories from fat than controls, while dominant animals ingested more calories from carbohydrates. These results suggest that psychosocial stress can be a risk factor for overeating and weight gain in mice. However, social status influences the extent to which an individual keeps up with adverse environment, influencing the vulnerability toward stress related disorders.


Subject(s)
Energy Metabolism/physiology , Psychology , Social Dominance , Stress, Psychological/complications , Animals , Blood Glucose/analysis , Body Weight , Calorimetry, Indirect , Diet , Eating , Fatty Acids, Nonesterified/blood , Male , Mice , Triglycerides/blood
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 60(8-9): 1685-705, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15248940

ABSTRACT

Gas analyzers based on tunable diode-laser spectroscopy (TDLS) provide high sensitivity, fast response and highly specific in situ measurements of several atmospheric trace gases simultaneously. Under optimum conditions even a shot noise limited performance can be obtained. For field applications outside the laboratory practical limitations are important. At ambient mixing ratios below a few parts-per-billion spectrometers become more and more sensitive towards noise, interference, drift effects and background changes associated with low level signals. It is the purpose of this review to address some of the problems which are encountered at these low levels and to describe a signal processing strategy for trace gas monitoring and a concept for in situ system calibration applicable for tunable diode-laser spectroscopy. To meet the requirement of quality assurance for field measurements and monitoring applications, procedures to check the linearity according to International Standard Organization regulations are described and some measurements of calibration functions are presented and discussed.


Subject(s)
Spectrum Analysis/methods , Air Pollutants/analysis , Atmosphere/analysis , Gases/analysis , Lasers , Sensitivity and Specificity , Signal Processing, Computer-Assisted , Spectrum Analysis/instrumentation , Spectrum Analysis/standards , Spectrum Analysis/statistics & numerical data
19.
Dev Psychobiol ; 44(4): 230-7, 2004 May.
Article in English | MEDLINE | ID: mdl-15103733

ABSTRACT

Short- and long-term effects of brief maternal separation, maternal exposure to novel male odor, and standard rearing were compared in NMRI mice. The first condition consisted of 15 min of daily exposure of pups to clean bedding (CB), and the second condition consisted of 15 min of mothers' exposure to the odor of strange males (SM), for 14 days after birth starting from postnatal Day 1. Thus, both conditions entailed the same period of maternal separation. A control mother-offspring group was left undisturbed (nonhandled, N-H). Corticosterone levels of mothers and pups were measured at the end of the last manipulation session. Corticosterone levels were higher in SM mothers, differing from both those of CB and of control dams; CB pups showed the highest corticosterone levels in comparison with the pups belonging to the other groups. Maternal behavior observed as furthest as possible from the daily separation session did not differ among the three groups. The behavioral response to 0.5 mg/kg of apomorphine in 15-day-old pups was enhanced in both CB and SM animals, which suggests an alteration of dopaminergic functioning. Finally, adult CB and SM male mice showed an increase in the percentage of time and entries into the open arms of the plus-maze in comparison to nonhandled males. This study indicates that exposure to ecologically relevant stimuli elicited a stress response in lactating dams. This "social stress" brings about short- and long-term effects in the offspring, even in the absence of any direct manipulation of the pups.


Subject(s)
Behavior, Animal/physiology , Mothers , Stress, Physiological/psychology , Animals , Animals, Newborn , Corticosterone/blood , Dopamine/blood , Mice
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 58(11): 2361-72, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12353685

ABSTRACT

Currently available semiconductor lasers for spectroscopy in the near- and mid-infrared region based on direct band-to-band transitions as gallium-arsenide, indium-phosphide, antimonides and lead-salt containing compounds will be discussed together with the main features of different tunable diode-laser absorption spectrometers for trace gas analysis. Measurements of atmospheric carbon dioxide with a room-temperature 2 microm indium-phosphide laser, applications of antimonide lasers for methane and formaldehyde sensing in the 3-4 microm range and a fast chemical sensor for methane flux measurements based on lead-salt diode-lasers operating near 7.8 microm will be presented.


Subject(s)
Antimony/chemistry , Indium/chemistry , Lead/chemistry , Phosphines/chemistry , Spectrophotometry, Infrared/instrumentation
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