Diagnostic applications of molecular and serological assays for bluetongue and African horse sickness.

The availability of rapid, highly sensitive and specific molecular and serologic diagnostic assays, such as competitive enzyme-linked immunosorbent assay (cELISA), has expedited the diagnosis of emerging transboundary animal diseases, including bluetongue (BT) and African horse sickness (AHS), and facilitated more thorough characterisation of their epidemiology. The development of assays based on real-time, reverse-transcription polymerase chain reaction (RT-PCR) to detect and identify the numerous serotypes of BT virus (BTV) and AHS virus (AHSV) has aided in-depth studies of the epidemiology of BTV infection in California and AHSV infection in South Africa. The subsequent evaluation of pan-serotype, real-time, RT-PCR-positive samples through the use of serotype-specific RT-PCR assays allows the rapid identification of virus serotypes, reducing the need for expensive and time-consuming conventional methods, such as virus isolation and serotype-specific virus neutralisation assays. These molecular assays and cELISA platforms provide tools that have enhanced epidemiologic surveillance strategies and improved our understanding of potentially altered Culicoides midge behaviour when infected with BTV. They have also supported the detection of subclinical AHSV infection of vaccinated horses in South Africa. Moreover, in conjunction with whole genome sequence analysis, these tests have clarified that the mechanism behind recent outbreaks of AHS in the AHS-controlled area of South Africa was the result of the reversion to virulence and/or genome reassortment of live attenuated vaccine viruses. This review focuses on the use of contemporary molecular diagnostic assays in the context of recent epidemiologic studies and explores their advantages over historic virus isolation and serologic techniques.

La disponibilité d'essais diagnostiques moléculaires et sérologiques rapides, hautement sensibles et spécifiques tels que l'épreuve immuno-enzymatique de compétition (ELISAc), a accéléré le diagnostic des maladies animales transfrontalières émergentes, dont la fièvre catarrhale ovine (FCO) et la peste équine, et contribué à dresser un tableau épidémiologique plus complet de ces maladies. Grâce à la mise au point d'essais basés sur l'amplification en chaîne par polymérase en temps réel couplée à une transcription inverse (RT­PCR) qui permettent de détecter et d'identifier les nombreux sérotypes du virus de la fièvre catarrhale du mouton et du virus de la peste équine, des études approfondies ont pu être conduites sur l'épidémiologie de l'infection par le virus de la fièvre catarrhale du mouton en Californie et de l'infection par le virus de la peste équine en Afrique du Sud. L'évaluation postérieure des échantillons positifs à une RT­PCR en temps réel de groupe (détectant le virus quel que soit le sérotype) au moyen de RT­PCR spécifiques de chaque sérotype permet d'identifier rapidement le sérotype causal et de limiter le recours à des méthodes classiques onéreuses et chronophages comme l'isolement viral ou les essais de neutralisation virale spécifiques de chaque sérotype. Les outils fournis par ces essais moléculaires et par les plateformes ELISAc ont renforcé les stratégies de surveillance épidémiologique et permis de mieux connaître les altérations potentielles de comportement chez les tiques Culicoides infectées par le virus de la fièvre catarrhale du mouton. Ils ont également contribué à détecter les cas d'infection asymptomatique par le virus de la peste équine chez des chevaux vaccinés en Afrique du Sud. En outre, associés avec l'analyse de séquences du génome entier, ces tests ont révélé que le mécanisme sous-jacent aux récents foyers de peste équine dans la zone de contrôle en Afrique du Sud correspondait à une réversion vers la virulence et/ou à un réassortiment du génome des souches de vaccin à virus vivant atténué. Les auteurs passent en revue l'utilisation des essais de diagnostic moléculaire de nouvelle génération dans le contexte de récentes études épidémiologiques et cherchent à établir leurs avantages par rapport aux techniques classiques d'isolement viral et de recherche sérologique.

La existencia de ensayos moleculares y serológicos de diagnóstico rápidos y de gran sensibilidad y especificidad, como el ensayo inmunoenzimático de competición (ELISAc), ha acelerado el diagnóstico de enfermedades animales transfronterizas emergentes, como la lengua azul o la peste equina, y facilitado una caracterización más exhaustiva de su epidemiología. La creación de ensayos basados en la reacción en cadena de la polimerasa acoplada a transcripción inversa (RT?PCR) en tiempo real para detectar y caracterizar los numerosos serotipos de los virus de la lengua azul y la peste equina ha ayudado a estudiar a fondo la epidemiología de sendos episodios infecciosos causados por el virus de la lengua azul en California y por el virus de la peste equina en Sudáfrica. El subsiguiente análisis de las muestras positivas a la prueba de RT?PC en tiempo real de cualquier serotipo con empleo de ensayos RT?PCR dirigidos específicamente contra uno u otro serotipo permite identificar rápidamente los serotipos víricos, lo que hace menos necesario el uso de métodos convencionales más caros y largos, como el aislamiento del virus o técnicas de neutralización vírica adaptadas específicamente a un serotipo. Estos dispositivos de ensayo molecular o de ELISAc ponen a nuestra disposición herramientas que potencian las estrategias de vigilancia epidemiológica y ayudan a conocer mejor las eventuales alteraciones del comportamiento de los jejenes Culicoides al ser infectados por el virus de la lengua azul. Estas técnicas han ayudado también a detectar en Sudáfrica casos de infección asintomática por el virus de la peste equina en caballos vacunados. Estas pruebas, además, empleadas en combinación con el análisis de secuencias genómicas completas, han servido para aclarar que el mecanismo subyacente a los recientes brotes de peste equina surgidos en la zona de Sudáfrica donde la enfermedad estaba bajo control fue fruto de la reversión a la virulencia y/o el reordenamiento genómico de virus vacunales atenuados. Los autores, centrándose en el uso de modernos ensayos moleculares de diagnóstico como parte de recientes estudios epidemiológicos, examinan las ventajas que ofrecen en comparación con las tradicionales técnicas serológicas y de aislamiento vírico.

Trap placement and attractant choice affect capture and create sex and parity biases in collections of the biting midge, Culicoides sonorensis.

Culicoides sonorensis Wirth & Jones (Diptera: Ceratopogonidae) is the primary North American vector of bluetongue virus (BTV), which can cause high morbidity and mortality in ruminant livestock or wildlife. Worldwide, most Culicoides surveillance relies on light (usually UV) traps typically placed near animals or larval development sites. However, the trapping method can cause sex, species and parity biases in collections. We collected C. sonorensis from three dairies in California using suction traps baited with CO2 , UV light or CO2 + UV placed near animals, wastewater ponds, or in fields. Higher numbers of parous females were collected using CO2 + UV traps, although this difference was only significant on one dairy. UV traps were poor at collecting nulliparous females, but the addition of UV to a trap increased the abundance of males in a collection. Traps set in open fields collected significantly higher numbers of males and females than in either of the other two locations. In some cases, there was a significant interaction between the trap type and site. We discuss the limitations of traditional trapping methodologies for C. sonorensis and make suggestions for vector surveillance.

Lack of Evidence for Laboratory and Natural Vertical Transmission of Bluetongue Virus in Culicoides sonorensis (Diptera: Ceratopogonidae).

Culicoides sonorensis (Wirth & Jones) is the principal North American vector of bluetongue virus (BTV). BTV infection of livestock is distinctly seasonal (late summer and fall) in temperate regions of the world such as California, which has led to speculation regarding vertical transmission of the virus within the midge vector as a potential mechanism for interseasonal maintenance ("overwintering") of the virus. To evaluate potential vertical transmission of BTV in its midge vector, we fed adult midges BTV-spiked blood and used a BTV-specific quantitative reverse transcriptase polymerase chain reaction assay to evaluate parent, egg, and progeny stages of laboratory-reared C. sonorensis for the presence of viral nucleic acid. Whereas BTV nucleic acid was weakly detected in egg batches of virus-fed female midges, virus was never detected in subsequent progeny stages (larvae, pupae, and F1 generation adults). Similarly, BTV was not detected in pools of larvae collected from the waste-water lagoon of a BTV-endemic dairy farm in northern California during the seasonal period of virus transmission. Collectively, these results indicate that BTV is not readily transmitted vertically in C. sonorensis, and that persistence of the virus in long-lived parous female midges is a more likely mechanism for overwintering of BTV in temperate regions.

Bluetongue.

Summary Bluetongue (BT) is an arthropod-transmitted viral disease of non-African ungulates, principally sheep. The disease results from vascular injury analogous to that of human haemorrhagic viral fevers, with characteristic tissue infarction, haemorrhage, vascular leakage, oedema, and hypovolaemic shock. Importantly, BT is not zoonotic. Bluetongue virus (BTV) infection of ruminants and vector Culicoides midges is endemic throughout many tropical and temperate regions of the world; however, within this global range the virus exists within relatively discrete ecosystems (syn. episystems) where specific constellations of BTV serotypes are spread by different species of biting Culicoides midges. Recently discovered goat-associated BTVs, notably BTV serotype 25 (BTV-25) in central Europe, appear to have distinctive biological properties and an epidemiology that is not reliant on Culicoides midges as vectors for virus transmission. Bluetongue virus infection of ruminants is often subclinical, but outbreaks of severe disease occur regularly at the upper and lower limits of the virus's global range, where infection is distinctly seasonal. There have been recent regional alterations in the global distribution of BTV infection, particularly in Europe. It is proposed that climate change is responsible for these events through its impact on vector midges. However, the role of anthropogenic factors in mediating emergence of BTV into new areas remains poorly defined; for example, it is not clear to what extent anthropogenic factors were responsible for the recent translocation to northern and eastern Europe of live attenuated vaccine viruses and an especially virulent strain of BTV-8 with distinctive properties. Without thorough characterisation of all environmental and anthropogenic drivers of the recent emergence of BT in northern Europe and elsewhere, it is difficult to predict what the future holds in terms of global emergence of BTV infection. Accurate and convenient laboratory tests are available for the sensitive and specific serological and virological diagnosis of BTV infection and confirmation of BT in animals. Prevention and control strategies for BT are largely reactive in nature, and typically are reliant on vaccination of susceptible livestock and restrictions on animal trade and movement.

Estimating Culicoides sonorensis biting midge abundance using digital image analysis.

ImageJ is an open-source software tool used for a variety of scientific objectives including cell counting, shape analysis and image correction. This technology has previously been used to estimate mosquito abundance in surveillance efforts. However, the utility of this application for estimating abundance or parity in the surveillance of Culicoides spp. (Diptera: Ceratopogonidae) has not yet been tested. Culicoides sonorensis (Wirth and Jones), a biting midge often measuring 2.0-2.5 mm in length, is an economically important vector of ruminant arboviruses in California. Current surveillance methods use visual sorting for the characteristics of midges and are very time-intensive for large studies. This project tested the utility of ImageJ as a tool to assist in gross trap enumeration as well as in parity analysis of C. sonorensis in comparison with traditional visual methods of enumeration using a dissecting microscope. Results confirmed that automated counting of midges is a reliable means of approximating midge numbers under certain conditions. Further evaluation confirmed accurate and time-efficient parity analysis in comparison with hand sorting. The ImageJ software shows promise as a tool that can assist and expedite C. sonorensis surveillance. Further, these methods may be useful in other insect surveillance activities.

Health-related quality of life anticipated with different management strategies for febrile neutropenia in adult cancer patients.

PURPOSE: To describe anticipated health-related quality of life (HRQL) for different hypothetical strategies of febrile neutropenia (FN) management in adult cancer patients. METHODS: Seventy-eight adult cancer patients were enrolled. Our study considered four different hypothetical treatment strategies for FN: (1) entire inpatient management with intravenous (IV) antibiotics; (2) oral treatment at home after an initial observation in hospital with IV antibiotics; (3) entire outpatient management with IV antibiotics; and (4) entire outpatient management with oral antibiotics. Initially, patients were asked to rank the different treatment strategies for FN based on their personal preference. Subsequently, HRQL was rated using visual analog scale (VAS), time trade-off (TTO), and willingness-to-pay (WTP). RESULTS: Seventy-five percent of all respondents preferred an outpatient strategy for FN (36% oral, 21% intravenous, 18% early discharge). Further, outpatient strategies were associated with higher mean VAS scores (possible range 0-10) (oral: 6.1 (standard deviation (SD) 3.1); intravenous: 6.2 (SD 2.2); early discharge: 5.7 (SD 2.1)) as compared to inpatient care (5.3 (SD 2.9)). On the aggregate level, patients were willing to give up between 9 and 10 weeks of their life (TTO; corresponding to <1% of remaining life expectancy) and to pay between $255 and $327 Canadian dollars (WTP) to avoid treatment in hospital. CONCLUSIONS: Our study indicates that the majority of adult cancer patients would prefer an outpatient strategy for FN. However, patients' preferences vary substantially at the individual level. Implementation of outpatient strategies into routine clinical practice should consider this variability.

[COPD inhaled therapy narrative review]. / Revisión narrativa de la terapia inhalatoria en la EPOC.

Inhaled therapy with long-acting bronchodilators is the base of pharmacological treatment in COPD. In order to find out those that offer better control, a search was carried out in Medline (Pubmed). Comparative studies of inhaler therapy in COPD patients were analyzed. The comparison between the fixed combination LABA/LAMA versus LABA/CI in non-exacerbating patients, revealed a better control with LABA/LAMA. Within the LABA/CI combinations, budesonide/formoterol combination offered better control. LAMA inhalers revealed no great differences, but when compared to LABA, it offered a better control. Regarding triple therapy in a single device, was superior to double therapy and to triple therapy in two devices, with no relevant differences among the available combinations.

Repatriation of a historical North Atlantic right whale habitat during an era of rapid climate change.

Climate change is affecting species distributions in space and time. In the Gulf of Maine, one of the fastest-warming marine regions on Earth, rapid warming has caused prey-related changes in the distribution of the critically endangered North Atlantic right whale (Eubalaena glacialis). Concurrently, right whales have returned to historically important areas such as southern New England shelf waters, an area known to have been a whaling ground. We compared aerial survey data from two time periods (2013-2015; 2017-2019) to assess trends in right whale abundance in the region during winter and spring. Using distance sampling techniques, we chose a hazard rate key function to model right whale detections and used seasonal encounter rates to estimate abundance. The mean log of abundance increased by 1.40 annually between 2013 and 2019 (p = 0.004), and the mean number of individuals detected per year increased by 2.23 annually between 2013 and 2019 (R2 = 0.69, p = 0.001). These results demonstrate the current importance of this habitat and suggest that management options must continually evolve as right whales repatriate historical habitats and potentially expand to new habitats as they adapt to climate change.

Health-related quality of life anticipated with different management strategies for paediatric febrile neutropaenia.

BACKGROUND: To describe (1) anticipated health-related quality of life during different strategies for febrile neutropaenia (FN) management and (2) attributes of those preferring inpatient management. METHODS: Respondents were parents of children 0-18 years and children 12-18 years receiving cancer treatment. Anticipated health-related quality of life was elicited for four different FN management strategies: entire inpatient, early discharge, outpatient oral and outpatient intravenous (i.v.) therapy. Tools used to measure health-related quality of life were visual analogue scale (VAS), willingness to pay and time trade off. RESULTS: A total of 155 parents and 43 children participated. For parents, median VAS scores were highest for early discharge (5.9, interquartile range 4.4-7.2) and outpatient i.v. (5.9, interquartile range 4.4-7.3). For children, median scores were highest for early discharge (6.1, interquartile range 4.6-7.2). In contrast, the most commonly preferred strategy for parents and children was inpatient in 55.0% and 37.2%, respectively. Higher current child health-related quality of life was associated with a stronger preference for outpatient management. CONCLUSION: Early discharge and outpatient i.v. management are associated with higher anticipated health-related quality of life, although the most commonly preferred strategy was inpatient care. This data may help with determining more cost-effective strategies for paediatric FN.

Brain metastases from lung cancer responding to erlotinib: the importance of EGFR mutation.

Median survival of patients with brain metastases from nonsmall cell lung cancer (NSCLC) is poor and more effective treatments are urgently needed. We have evaluated the efficacy of erlotinib in this setting and its association with activating mutations in the epidermal growth factor receptor (EGFR) gene. We retrospectively identified patients with NSCLC and brain metastases treated with erlotinib. EGFR mutations in exons 19 and 21 were analysed by direct sequencing. Efficacy and tolerability were compared according to EGFR mutational status. 69 NSCLC patients with brain metastases were identified, 17 of whom harboured EGFR mutations. Objective response rate in patients with EGFR mutations was 82.4%; no responses were observed in unselected patients (p<0.001). Median (95% CI) time to progression within the brain for patients harbouring EGFR mutations was 11.7 (7.9-15.5) months, compared to 5.8 (5.2-6.4) months for control patients whose EGFR mutational status had not been assessed (p<0.05). Overall survival was 12.9 (6.2-19.7) months and 3.1 (2.5-3.9) months (p<0.001), respectively. The toxicity of erlotinib was as expected and no differences between cohorts were observed. Erlotinib is active in brain metastases from NSCLC; this clinical benefit is related to the presence of activating mutations in exons 19 or 21 of the EGFR gene.

Live predator stress in adolescence results in distinct adult behavioral consequences and dorsal diencephalic brain activation patterns.

Exposure to traumatic events during childhood increases the risk of adult psychopathology, including anxiety, depression, alcohol use disorders and their co-morbidity. Early life trauma also results in increased symptom complexity, treatment resistance and poor treatment outcomes. The purpose of this study was to establish a novel rodent model of adolescent stress, based on an ethologically relevant life-threatening event, live predator exposure. Rats were exposed to a live predator for 10 min. at three different time points (postnatal day (PND)31, 46 and 61). Adult depression-, anxiety-like behaviors and ethanol consumption were characterized well past the last acute stress event (two weeks). Behavioral profiles across assessments were developed to characterize individual response to adolescent stress. CNS activation patterns in separate groups of subjects were characterized after the early (PND31) and last predator exposure (PND61). Subjects exposed to live-predator adolescent stress generally exhibited less exploratory behavior, less propensity to venture into open spaces, a decreased preference for sweet solutions and decreased ethanol consumption in a two-bottle preference test. Additional studies demonstrated blunted cortisol response and CNS activation patterns suggestive of habenula, rostromedial tegmental (RMTg), dorsal raphe and central amygdala involvement in mediating the adult consequences of adolescent stress. Thus, adolescent stress in the form of live-predator exposure results in significant adult behavioral and neurobiological disturbances. Childhood trauma, its impact on neurodevelopment and the subsequent development of mood disorders is a pervasive theme in mental illness. Improving animal models and our neurobiological understanding of the symptom domains impacted by trauma could significantly improve treatment strategies.

Two-leg squat jumps in water: an effective alternative to dry land jumps.

The current study was designed to quantify and compare the kinetic parameters of two-leg squat jumps carried out on dry land, in water and in water using area devices that increase drag force. Twelve junior female handball players who had been competing at national level for the previous two years volunteered to participate in the study. Intensity of the two-leg squat jump was examined using a force plate (9 253-B11, Kistler Instrument AG, Winterthur, Switzerland) in three different conditions: on dry land, in water and in water using devices. An ANOVA with repeated measurements (condition) was applied to establish differences between the three jumps. The results show that peak impact force and impact force rate for the water jumps was lower than for the dry land jumps (p<0.05), while peak concentric force was higher for the water jumps than the dry land jumps (p<0.05). In addition, no statistically significant differences were found between water jumps for these variables (p>0.05). These results indicate that water provides an ideal environment for carrying out jumps, as the variables associated with the exercise intensity are boosted, while those related to the impact force are reduced and this fact could be less harmful.

The rostromedial tegmental nucleus modulates the development of stress-induced helpless behavior.

A growing body of clinical and preclinical research suggests that structural and functional changes in the habenula, a component of the epithalamus, are associated with major depressive disorder. A major excitatory, efferent projection from the habenula targets the rostromedial tegmentum (RMTg), a mesopontine region that provides significant input to the ventral tegmentum and raphe nuclei. While the RMTg contributes to monoaminergic responses to aversive events, its role in stress-based animal models of depression has yet to be determined. In the present study, we test the hypothesis that the RMTg is a component of the circuitry mediating the development of a maladaptive behavior in which rats repeatedly exposed to inescapable footshock, fail to avoid or escape the same stressor when subsequently given the opportunity to do so. Excitotoxic lesions of the RMTg significantly diminished the frequency of these escape failures 24 h after exposure to inescapable footshock. Conversely, electrical stimulation of the Hb during the initial uncontrollable aversive event, a manipulation that enhances excitatory input to the RMTg, increased the number of trials in which subjects failed to escape an aversive stimulus when presented the option 24 h later. These complementary results provide evidence supporting a role for the RMTg in the expression of stress-induced helpless phenotype and are an important step in understanding the contribution made by this region to the development of depression-related maladaptive behaviors.

Is prostatic biopsy as safe as we think? Epidural abscess following prostatic biopsy.

Spinal epidural abscess is an infectious disorder with high morbidity and mortality rates, which is often associated with delayed diagnosis. We report a case of a 73-year-old man with cervical pyogenic spondylodiscitis complicated with epidural abscess following a prostatic biopsy. Clinical presentation included fever, malaise, neck rigidity in all axes, minor paresis of the right arm, and gait ataxia. A cervical vertebral magnetic resonance imaging (MRI) scan showed pyogenic spondylodiscitis with an epidural abscess. Blood, urine, and cerebrospinal fluid cultures were sterile. The patient was treated with intravenous vancomycin, metronidazole, and ceftazidime for 4 weeks, and was discharged from the hospital and treated with oral cloxacillin, metronidazole, and cefixime for another 2 weeks. His neurological symptoms disappeared completely, and he walked normally, without support. It is important for clinicians to be alert to symptoms accompanying back pain following a prostatic biopsy and to consider the possibility of a diagnosis of spinal abscess.

Treatment data and technical process challenges for practical big data efforts in radiation oncology.

The term Big Data has come to encompass a number of concepts and uses within medicine. This paper lays out the relevance and application of large collections of data in the radiation oncology community. We describe the potential importance and uses in clinical practice. The important concepts are then described and how they have been or could be implemented are discussed. Impediments to progress in the collection and use of sufficient quantities of data are also described. Finally, recommendations for how the community can move forward to achieve the potential of big data in radiation oncology are provided.

Effects of two-stage weaning with nose flap devices applied to calves on cow body condition, calf performance, and calf humoral immune response.

The effects of nose flap devices in calves before dam separation on cow BCS, pre- and postseparation calf performance, and humoral immune response were compared with traditional weaning. Primiparous and multiparous Angus and Hereford cows ( = 113) and their Angus, Hereford, and Angus × Hereford calves (179.4 ± 3.92 kg and 161 ± 22.7 d of age) were used. Cow-calf pairs were allocated to 1 of 2 treatments in a completely randomized design: 1) nose flap for 21 d before separation from the dam (NF) or 2) no nose flap for 21 d before separation from the dam (CON). Calves were separated from dams on d 0, and calves were placed in group feed-yard pens for 28 d. A subset ( = 75) of weaned calves were placed into 1 of 8 pens to evaluate DMI. Cow BCS was measured on d -21 and 56, and calves were given modified live vaccinations (d -21 and 1), challenged with ovalbumin (OVA; d 1), and weighed (d -21, 1, 7, 14, 21, and 28). In addition, blood samples were collected (d -21, 1, 14, and 28) to measure primary humoral immune response. Control calves tended to have greater BW on d 14 ( = 0.09) and 21 ( = 0.07) than NF calves, and CON calves had greater ( < 0.05) ADG from d -21 to 1 vs. NF calves. Treatments did not differ ( ≥ 0.27) for postweaning DMI, G:F, or morbidity. Serum neutralization tests for bovine viral diarrhea virus type 1 (BVDV-1) and bovine herpesvirus type 1 (BHV-1) were used to measure humoral response to a viral vaccination. Serum antibody titers to BVDV-1 for CON calves tended ( = 0.08) to be greater on d 1 and were greater ( < 0.05) by d 28 vs. NF calves. By d 28, a greater percentage ( < 0.05) of CON calves seroconverted for BVDV-1 than NF calves (82.1 vs. 66.7%, respectively). Serum antibody titers for BHV-1 were greater ( < 0.05) on d 1 and 28 for CON vs. NF calves. Humoral immune response to OVA during the 28-d postseparation period from the dam was evaluated in a subset ( = 57) of calves. There was no difference ( = 0.92) in OVA-specific IgG between treatments on d 14 or 28 ( = 0.76); however, OVA-specific IgM was greater ( < 0.05) in CON vs. NF calves on d 28. Results indicate that nose flap devices did not influence feed intake, feed efficiency, or morbidity during the initial postseparation period from the dam. However, preweaning ADG, serum BVDV-1 and BHV-1 titers, and humoral immune response to OVA were decreased in calves that received the nose flap treatment.

Immunoassay based on surface plasmon oscillations.

An in situ immunoassay technique is described which is sensitive to specific binding to surface immobile antigen or antibody. The phenomena of surface plasmon oscillations are shown to be sensitive to antigen-antibody binding on a substrate. An advantage of the technique is that no molecular labeling is required. The technique allows the detection of the presence of approximately 6 X 10(8) molecules on the approximately 1 mm2 area of detection (approximately 1.5 X 10(-8) g/cm2). An elementary apparatus is described which allows the kinetics of the antigen-antibody binding to be accurately recorded in real time. A detailed example is presented. A second version of the apparatus of similar accuracy with improved temporal resolution is described.

Natural segmentation of the locomotor behavior of drug-induced rats in a photobeam cage.

Recently, Drai et al. (J Neurosci Methods 96 (2000) 119) have introduced an algorithm that segments rodent locomotor behavior into natural units of 'staying in place' (lingering) behavior versus going between places (progression segments). This categorization, based on the maximum speed attained within the segment, was shown to be intrinsic to the data, using the statistical method of Gaussian Mixture Model. These results were obtained in normal rats and mice using very large (650 or 320 cm) circular arenas and a video tracking system. In the present study, we reproduce these results with amphetamine, phencyclidine and saline injected rats, using data measured by a standard photobeam tracking system in square 45 cm cages. An intrinsic distinction between two or three 'gears' could be shown in all animals. The spatial distribution of these gears indicates that, as in the large arena behavior, they correspond to the difference between 'staying in place' behavior and 'going between places'. The robustness of this segmentation over arena size, different measurement system and dose of two psychostimulant drugs indicates that this is an intrinsic, natural segmentation of rodent locomotor behavior. Analysis of photobeam data that is based on this segmentation has thus a potential use in psychopharmacology research.

Variables that affect productivity in school foodservices.

Productivity in school foodservice can be measured through the use of a statistical model designed to evaluate predictors of productivity. The model in this study utilized 6 productivity measures and 12 predictor variables which served to broaden the basis upon which school foodservice administrators can make sound decisions regarding productivity. Significant findings indicated that the number of employees producing meals should be kept to a minimum; contingencies inherent in each operating unit affect the total amount of labor time used to produce meals; managers should have at least a two-year certificate of training; menu steps should be kept to a minimum; the use of disposable ware may aid in keeping payroll cost at a controllable level.