Glass transitions and state diagram for freeze-dried pineapple

Glass transition temperature of freeze-dried pineapple conditioned by adsorption at various water activities at 25 degreesC was determined by differential scanning calorimetry (DSC). High moisture content samples corresponding to water activities higher than 0.9, obtained by liquid water addition, were also analysed. The DSC traces showed a well-visible shift in baseline at the glass transition temperature (T(g)). Besides, no ice formation was observed until water activity was equal to 0.75. For water activities lower than 0.88, the glass transition curve showed that T(g) decreased with increasing moisture content and the experimental data could be well-correlated by the Gordon-Taylor equation. For higher water activities, this curve exhibited a discontinuity, with suddenly increasing glass transition temperatures approaching a constant value that corresponds to the T(g) of the maximally freeze-concentrated amorphous matrix. The unfreezable water content was determined through melting enthalpy dependence on the sample moisture content.

AN ULTRASTRUCTURAL-STUDY ON THE ENDOCRINE PANCREAS OF CAIMAN-LATIROSTRIS, WITH SPECIAL REFERENCE TO PANCREATIC MOTILIN CELLS

Pancreatic endocrine cells of Caiman latirostris were investigated by electron microscopy using conventional and immunocytochemical methods. Ultrastructurally, four types of endocrine cells were classified according to the morphology of their secretory granules. Three types of endocrine cells were identified as either glucagon, insulin or somatostatin cells by the presence of such characteristic granules well established in mammals. The remaining endocrine cell type could not be classified by its ultrastructural features alone.Immunocytochemical observations confirmed the ultrastructural classification of glucagon, insulin and somatostatin cells. In addition, endocrine cells immunoreactive for either pancreatic polypeptide (PP) or motilin were identified. Morphometric analysis of PP- and motilin-immunoreactive granules demonstrated that they were the most polymorphous and smallest granules among the pancreatic endocrine cell granules. Although both PP and motilin granules closely resemble each other, motilin granules were smaller in size and more spherical in shape than PP granules.

Leukocyte and thrombocyte reference values for channel catfish (Ictalurus punctatus Raf), with an assessment of morphologic, cytochemical, and ultrastructural features

Background: Hematology tests are useful to evaluate physiologic disturbances in fish and can provide important information for the diagnosis and prognosis of disease. Objectives: the primary purpose of this study was to define reference intervals for thrombocytes and leukocytes in healthy channel catfish (Ictalurus punctactus). In addition, the morphologic, cytochernical, and ultrastructural features of blood cells were assessed. Methods: Blood samples (0.5 mL were collected into EDTA from 40 clinically healthy catfish on a commercial fish farm in Jaboticabal, Brazil. Thrombocyte, total WBC, and differential WBC counts were determined and reference intervals were calculated as the 25-95th percentiles of data. Thrombocyte and leukocyte morphology was assessed in blood smears stained with May Griinwald-Giemsa-Wright and ultrastructurally by transmission electron microscopy. Cytochemical staining patterns were described using periodic acid-Schiff (PAS), peroxidase, nonspecific esterase, alkaline phosphatase, and toluidine blue. Results: Reference intervals were as follows: thrombocytes 58,802-99,569/mu L; total WBCs 27,460-41,523/mu L; lymphocytes 5380-11,581/mu L; monocytes 2949-7459/mu L; neutrophils 12,529-22,748/mu L, and basophils 736-2003/mu L. Neutrophils were positive for peroxidase and PAS; monocytes were positive for nonspecific esterase; and basophils were positive with toluidine blue. Conclusion: the morphologic and staining features of neutrophils and monocytes of channel catfish are similar to those of mammals, and the presence of basophils in this species was verified. These reference intervals and morphologic findings provide a foundation for future investigations on the functions and alterations of blood cells in channel catfish.

CLINICAL BIOCHEMICAL DETERMINATIONS IN THE MANGALARGA-PAULISTA HORSE - REFERENCE VALUES

Biochemical values are widely related with environmental agents, sex and age, and are used in disease diagnosis. Numerous reports have been published on the biochemical parameters of different breeds of horses. However, there is a paucity of information concerning Cu-Zn superoxide dismutase (SOD), ceruloplasmin, copper and zinc determinations in the serum. Blood samples from a total of 60 horses of the Mangalarga-Paulista breed, representing three age groups (0 to 4 months old, 6 to 18 months old and adult) were examined. Male horses have a higher mean value of SOD, ceruloplasmin and copper than do females. No significant sex-related difference was observed in serum zinc content of weaned and adult horses. SOD activity was significantly higher in adult animals. Since SOD has a protective effect against superoxide free radical toxicity and possesses anti-inflammatory activity, it is reasonable to assume that the increased activity of this enzyme may be due to an adaptation mechanism which protects the adult animal against oxygen toxicity.

Mnltiloop Controller and Reference Generator for a Dynamic Voltage Restorer Implementation

This paper deals with the design and analysis of a Dynamic Voltage Restorer output voltage control. Such control is based on a multiloop strategy, with an inner current PID regulator and an outer P+Resonant voltage controller. The inner regulator is applied on the output inductor current. It will be also demonstrated how the load current behavior may influence in the DVR output voltage, which. justifies the need for the resonant controller. Additionally, it will be discussed the application of a modified algorithm for the identification of the DVR voltage references, which is based on a previously presented positive sequence detector. Since the studied three-phase DVR is assumed to be based on three identical H-bridge converters, all the analysis and design procedures were realized by means of single-phase equivalent circuits. The discussions and conclusions are supported by theoretical calculations, nonlinear simulations and some experimental results.

An integrated database on ticks and tick-borne zoonoses in the tropics and subtropics with special reference to developing and emerging countries

Tick-borne zoonoses (TBZ) are emerging diseases worldwide. A large amount of information (e.g. case reports, results of epidemiological surveillance, etc.) is dispersed through various reference sources (ISI and non-ISI journals, conference proceedings, technical reports, etc.). An integrated database-derived from the ICTTD-3 project (http://www.icttd.nl)-was developed in order to gather TBZ records in the (sub-)tropics, collected both by the authors and collaborators worldwide. A dedicated website (http://www.tickbornezoonoses.org) was created to promote collaboration and circulate information. Data collected are made freely available to researchers for analysis by spatial methods, integrating mapped ecological factors for predicting TBZ risk. The authors present the assembly process of the TBZ database: the compilation of an updated list of TBZ relevant for (sub-)tropics, the database design and its structure, the method of bibliographic search, the assessment of spatial precision of geo-referenced records. At the time of writing, 725 records extracted from 337 publications related to 59 countries in the (sub-)tropics, have been entered in the database. TBZ distribution maps were also produced. Imported cases have been also accounted for. The most important datasets with geo-referenced records were those on Spotted Fever Group rickettsiosis in Latin-America and Crimean-Congo Haemorrhagic Fever in Africa. The authors stress the need for international collaboration in data collection to update and improve the database. Supervision of data entered remains always necessary. Means to foster collaboration are discussed. The paper is also intended to describe the challenges encountered to assemble spatial data from various sources and to help develop similar data collections.

Chromosome banding patterns of four species of bats, with special reference to a case of X-autosome translocation

The karyotypes of 4 species of bats, Artibeus lituratus (Phyllostomatidae), Pipistrellus pipistrellus (Vespertilionidae), Pteropus alecto and P. giganteus (Pteropodidae), were studied after several banding techniques. For A. lituratus, in which an X-autosome translocation was observed, an analysis of the replication pattern in the rearranged chromosome was also made after BrdU incorporation.

Comments, with reply on 'Continuous time relay-controlled model reference adaptive-system' by A. Abdulkareem and R. Nagarajam

An adaptive scheme is shown by the authors of the above paper (ibid. vol. 71, no. 2, pp. 275-276, Feb. 1983) for continuous time model reference adaptive systems (MRAS), where relays replace the usual multipliers in the existing MRAS. The commenter shows an error in the analysis of the hyperstability of the scheme, such that the validity of this configuration becomes an open question.

Population analysis of susceptibility to propolis in reference strains of Staphylococcus aureus and Escherichia coli

Susceptibility to several ethanolic extracts of propolis (EEP) concentrations was tested with the population analysis technique in reference strains of Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 35218). The results of these tests showed that all bacteria were killed by EEP concentrations approximately equal or higher (2.0% v/v - S. aureus; 10.0% v/v - E. coli) than the respective minimal inhibitory concentrations (MIC). Regarding the susceptibility to propolis, there was a homogeneity of data with the respective time kill curves showing a clear bactericidal effect during 6 to 9 h of exposition.

Influence of nearest-neighbor Coulomb interactions on the phase diagram of the ferromagnetic Kondo model

The influence of a nearest-neighbor Coulomb repulsion of strength V on the properties of the ferromagnetic Kondo model is analyzed using computational techniques. The Hamiltonian studied here is defined on a chain using localized S = 1/2 spins, and one orbital per site. Special emphasis is given to the influence of the Coulomb repulsion on the regions of phase separation recently discovered in this family of models, as well as on the double-exchange-induced ferromagnetic ground state. When phase separation dominates at V= 0, the Coulomb interaction breaks the large domains of the two competing phases into small islands of one phase embedded into the other. This is in agreement with several experimental results, as discussed in the text. Vestiges of the original phase separation regime are found in the spin structure factor as incommensurate peaks, even at large values of V. In the ferromagnetic regime close to density n = 0.5, the Coulomb interaction induces tendencies to charge ordering without altering the fully polarized character of the state. This regime of charge-ordered ferromagnetism may be related with experimental observations of a similar phase by Chen and Cheong [Phys. Rev. Lett. 76, 4042 (1996)]. Our results reinforce the recently introduced notion [see, e.g., S. Yunoki et al., Phys. Rev. Lett. 80, 845 (1998)] that in realistic models for manganites analyzed with unbiased many-body techniques, the ground state properties arise from a competition between ferromagnetism and phase-separation - charge-ordering tendencies. ©1999 The American Physical Society.

Short-chain di-ureasil ormolytes doped with potassium triflate: Phase diagram and conductivity behavior

Di-urea cross-linked poly(oxyethylene)/siloxane hybrids, synthesized by the sol-gel process and containing a wide concentration range of potassium triflate, KCF3SO3, have been analyzed by x-ray diffraction and differential scanning calorimetry. The pseudo-phase diagram proposed has been taken into account in the interpretation of the complex impedance measurements. The xerogels prepared are obtained as transparent, thin monoliths. At room temperature the highest conductivity found was 2 × 10-6 Ω-1 cm-1.

Study of a hybrid solid oxide fuel cell: Energetic analysis and sankey diagram

In this paper a hybrid solid oxide fuel cell (SOFC) system is analyzed. This system applies a combined cycle utilizing gas turbine associated to a SOFC for rational decentralized energy production. Initially the relative concepts about the fuel cell are presented, followed by some chemical and technical informations such as the change of Gibbs free energy in isothermal fuel oxidation (or combustion) directly into electricity. This represents a very high fraction of the lower heating value (LHV) of a hydrocarbon fuel. In the next step a methodology for the study of SOFC associated with a gas turbine system is developed, considering the electricity and steam production for a hospital, as regard to the Brazilian conditions. This methodology is applied to energetic analysis. Natural gas is considered as a fuel. In conclusion, it is shown by a Sankey Diagram that the hybrid SOFC system may be an excellent opportunity to strengthen the decentralized energy production in Brazil. It is necessary to consider that the cogeneration in this version also is a sensible alternative from the technical point of view, demanding special methods of design, equipment selection and mainly of the contractual deals associated to electricity and fuel supply.

The mandibular lingula's position in children as a reference to inferior alveolar nerve block

Purpose: The objective of this study was to evaluate the position of the mandibular lingula (ML) to provide data for inferior alveolar nerve block techniques in children. Methods: One hundred fifty-four panoramic radiographs of 7- to 10-year-old boys and girls were analyzed. Measurements were taken from the ML to the occlusal plane, and the percentile distances of the ML to ramal borders were determined. Results: The distance between the ML and the occlusal plane showed a gradual increase, but only in the male group was it statistically significant. MLs ratio position on the ramus remained constant in all analyzed groups. In the 7-year-old group, the ML was observed above the occlusal plane in 70% of girls and 55% of boys. That percentage reached 85% of all children by age 10. Conclusions: The mandibular lingula's ratio position remained constant. Inferior alveolar anesthesia should be administered at least 6 mm above the occlusal plane in 7- to 8-year-old children, while 10 mm could be indicated for 9- to 10-year-old children. The mandibular lingula should be considered a reliable reference for further studies of inferior alveolar nerve block techniques.