Open-ZB: an open-source implementation of the IEEE 802.15.4/ZigBee protocol stack on TinyOS

The IEEE 802.15.4/ZigBee protocols are gaining increasing interests in both research and industrial communities as candidate technologies for Wireless Sensor Network (WSN) applications. In this paper, we present an open-source implementation of the IEEE 802.15.4/Zigbee protocol stack under the TinyOS operating system for the MICAz motes. This work has been driven by the need for an open-source implementation of the IEEE 802.15.4/ZigBee protocols, filling a gap between some newly released complex C implementations and black-box implementations from different manufacturers. In addition, we share our experience on the challenging problem that we have faced during the implementation of the protocol stack on the MICAz motes. We strongly believe that this open-source implementation will potentiate research works on the IEEE 802.15.4/Zigbee protocols allowing their demonstration and validation through experimentation.

Diversity in Teams: Source of Conflict or Source of Creativity? Investigating Hidden Mental Models

The workforce in organizations today is becoming increasingly diverse. Consequently the role of diversity management is heavily discussed with respect to the question how diversity influences the productivity of a group. Empirical studies show that on one hand there is a potential for increasing productivity but on the other hand it might be as well that conflicts arise due to the heterogeneity of the group. Usually according empirical studies are based on interviews, questionnaires and/or observations. These methods imply that answers are highly selective and filtered. In order to make the invisible visible, to have access to mental models of team members the paper will present an empirical study on the self-understanding of groups based on an innovative research method, called “mind-scripting”.

Serological and infection statuses of dogs from a visceral leishmaniasis-endemic area

OBJECTIVE This study investigated the serological status of dogs living in a visceral leishmaniasis-endemic area and its correlation with the parasitological condition of the animals.METHODS Canine humoral response was evaluated using the sera of 134 dogs by enzyme-linked immunosorbent assay and immunohistochemistry to detect parasites in the skin, lymph node, and spleen of the animals. The specific antibodies investigated were IgG, IgG1, IgG2, and IgE.RESULTS According to the parasitological, laboratory, and clinical findings, the dogs were placed into one of four groups: asymptomatic with (AP+, n = 21) or without (AP-, n = 36) Leishmania tissue parasitism and symptomatic with (SP+, n = 52) or without (SP-, n = 25) parasitism. Higher IgG and IgE levels were positively correlated with the infection condition and parasite load, but not with the clinical status. In all groups, total IgG was the predominant antibody, which occurred at the expense of IgG2 instead of IgG1. Most of the infected dogs tested positive for IgG (SP+, 98.1%; AP+, 95.2%), whereas this was not observed with IgE (SP+, 80.8%; AP+, 71.2%). The most relevant finding was the high positivity of the uninfected dogs for Leishmania-specific IgG (SP-, 60.0%; AP-, 44.4%), IgE (SP-, 44.0%; AP-, 27.8%), IgG1 (SP-, 28.0%; AP-, 22.2%), and IgG2 antibodies (SP-, 56.0%; AP-, 41.7%).CONCLUSIONS The serological status of dogs, as determined by any class or subclass of antibodies, did not accurately distinguish dogs infected with L. (L.) infantum chagasifrom uninfected animals. The inaccuracy of the serological result may impair not only the diagnosis, but also epidemiological investigations and strategies for visceral leishmaniasis control. This complex serological scenario occurring in a visceral leishmaniasis-endemic area highlights the challenges associated with canine diagnosis and points out the difficulties experienced by veterinary clinicians and coordinators of control programs.

Perceptually driven video error protection using a distributed source coding approach

In video communication systems, the video signals are typically compressed and sent to the decoder through an error-prone transmission channel that may corrupt the compressed signal, causing the degradation of the final decoded video quality. In this context, it is possible to enhance the error resilience of typical predictive video coding schemes using as inspiration principles and tools from an alternative video coding approach, the so-called Distributed Video Coding (DVC), based on the Distributed Source Coding (DSC) theory. Further improvements in the decoded video quality after error-prone transmission may also be obtained by considering the perceptual relevance of the video content, as distortions occurring in different regions of a picture have a different impact on the user's final experience. In this context, this paper proposes a Perceptually Driven Error Protection (PDEP) video coding solution that enhances the error resilience of a state-of-the-art H.264/AVC predictive video codec using DSC principles and perceptual considerations. To increase the H.264/AVC error resilience performance, the main technical novelties brought by the proposed video coding solution are: (i) design of an improved compressed domain perceptual classification mechanism; (ii) design of an improved transcoding tool for the DSC-based protection mechanism; and (iii) integration of a perceptual classification mechanism in an H.264/AVC compliant codec with a DSC-based error protection mechanism. The performance results obtained show that the proposed PDEP video codec provides a better performing alternative to traditional error protection video coding schemes, notably Forward Error Correction (FEC)-based schemes. (C) 2013 Elsevier B.V. All rights reserved.

Weather parameters and nosocomial bloodstream infection: a case-referent study

OBJECTIVE To evaluate if temperature and humidity influenced the etiology of bloodstream infections in a hospital from 2005 to 2010.METHODS The study had a case-referent design. Individual cases of bloodstream infections caused by specific groups or pathogens were compared with several references. In the first analysis, average temperature and humidity values for the seven days preceding collection of blood cultures were compared with an overall “seven-days moving average” for the study period. The second analysis included only patients with bloodstream infections. Several logistic regression models were used to compare different pathogens and groups with respect to the immediate weather parameters, adjusting for demographics, time, and unit of admission.RESULTS Higher temperatures and humidity were related to the recovery of bacteria as a whole (versus fungi) and of gram-negative bacilli. In the multivariable models, temperature was positively associated with the recovery of gram-negative bacilli (OR = 1.14; 95%CI 1.10;1.19) or Acinetobacter baumannii (OR = 1.26; 95%CI 1.16;1.37), even after adjustment for demographic and admission data. An inverse association was identified for humidity.CONCLUSIONS The study documented the impact of temperature and humidity on the incidence and etiology of bloodstream infections. The results correspond with those from ecological studies, indicating a higher incidence of gram-negative bacilli during warm seasons. These findings should guide policies directed at preventing and controlling healthcare-associated infections.

Inhibition of Aspergillus fumigatus and its biofilm by Pseudomonas aeruginosa is dependent on the source, phenotype and growth conditions of the bacterium

Aspergillus fumigatus (Af) and Pseudomonas aeruginosa (Pa) are leading fungal and bacterial pathogens, respectively, in many clinical situations. Relevant to this, their interface and co-existence has been studied. In some experiments in vitro, Pa products have been defined that are inhibitory to Af. In some clinical situations, both can be biofilm producers, and biofilm could alter their physiology and affect their interaction. That may be most relevant to airways in cystic fibrosis (CF), where both are often prominent residents. We have studied clinical Pa isolates from several sources for their effects on Af, including testing involving their biofilms. We show that the described inhibition of Af is related to the source and phenotype of the Pa isolate. Pa cells inhibited the growth and formation of Af biofilm from conidia, with CF isolates more inhibitory than non-CF isolates, and non-mucoid CF isolates most inhibitory. Inhibition did not require live Pa contact, as culture filtrates were also inhibitory, and again non-mucoid>mucoid CF>non-CF. Preformed Af biofilm was more resistant to Pa, and inhibition that occurred could be reproduced with filtrates. Inhibition of Af biofilm appears also dependent on bacterial growth conditions; filtrates from Pa grown as biofilm were more inhibitory than from Pa grown planktonically. The differences in Pa shown from these different sources are consistent with the extensive evolutionary Pa changes that have been described in association with chronic residence in CF airways, and may reflect adaptive changes to life in a polymicrobial environment.

Immunodiagnostic confirmation of hydatid disease in patients with a presumptive diagnosis of infection

Information obtained from the routine application of hydatid immunodiagnostic techniques in different clinical situations over a seven-year period is presented. The Immunoelectrophoresis test was used until it was replaced by the simpler, more sensitive and equally specific arc 5 double diffusion (DD5) test. Examination of sera from 1,888 patients with signs and/or symptoms compatible with hydatid disease revealed that the presurgical confirmation of Echinococcus granulosus infection is only obtained by detection of anti-antigen 5 antibodies. The latter were not found in 1,539 presumptive hydatidosis patients whose definitive diagnoses corresponded to other disease conditions. However, false positive latex agglutination test results were obtained in two cases. In all patients whose preoperative serum showed three or more uncharacteristic bands in the absence of anti-antigen 5 antibodies, hydatid cysts were found sur gically. DD5 testing of a fluid sample collected by puncture established its hydatid etiology. Post-operative monitoring of hydatidosis patients demonstrated that persistence of DD5-positivity two years after surgery established the presence of other cysts. Further evidence was obtained in patients with hydatid cysts in intrathoracic, abdominal or other locations associating cyst membrane integrity, antigen release and immunodiagnostic test positivity.

Photographic source for the history of portuguese-speaking Africa, 1870-1914

History in Africa, n.18, pág.67-82

Resistance of mice immunized with killed culture trypomastigotes against infection by insect-derived trypomastigotes of Trypanosoma cruzi

Mice immunized with heat or merthiolate-killed culture trypomastigotes of the non-virulent G strain were resistant to the challenge by insect-derived trypomastigotes of the CL strain of Trypanosoma cruzi. No parasitemia was detected, by direct microscopic examination of blood samples, in 90% of immunized mice while all control animals developed a high parasitemia. Trypsinization before heat-inactivation, or fixation with paraformaldehyde, apparently reduced the immunogenicity of the G strain trypomastigotes. Mice immunized with trypomastigotes treated by either of these procedures were not protected against infection by virulent T. cruzi. Analysis of the 13I-labeled surface proteins of G strain trypomastigotes inactivated by the various methods suggests that these components are involved in eliciting protective immunity against T. cruzi infection.

Congenital cytomegalovirus infection: occurrence in two socioeconomically distinct populations of a developing country

In São Paulo, Brazil, between November 1980 and July 1982, 1614 newborns of middle socioeconomic background and 1156 newborns of low socioeconomic background were examined for the occurrence of congenital cytomegalovirus (CMV) infection by isolation of virus from urine samples or detection of specific anti-CMV IgM in umbilical cord serum tested by immunofluorescence. In the low socioeconomic population prevalence of CMV complement-fixing antibodies in mothers was 84.4%(151/179) and the incidence of congenital infection assessed by virus isolation 0.98% (5/508), as compared with 0.46% (3/648) in the group of newborns tested by detection of specific anti-CMV IgM in umbilical cord-serum. In middle socioeconomic level population prevalence of CMV complement-fixing antibodies in mothers was 66.5% (284/427) and the incidence of CMV congenital infection was 0.39% (2/518) in the group of newborns screened by virus isolation and 0.18% (2/1096) in the group tested by detection of specific anti-CMV IgM. In the present study none of the 12 congenitally infected newborns presented clinical apparent disease at birth.

Schistosoma mansoni: comparative evaluation of different routes of experimental infection

Experiments were carried out with Sw albino mice and it was concluded that the percutaneous route via abdominal skin was significatively more efficient than tail immersion method and subcutaneous infection; the subcutaneous injection was significatively more efficient than the percutaneous infection through the tail; this latter and the intraperitoneal injection, resulted in similar infections, but were significatively less efficient than the others. Significative difference was also observed in the comparison between the subcutaneous route and percutaneous infection through ear pinna. The influence of the site of skin infection by percutaneous route was also discussed.

The effect of Schistosoma mansoni infection on child morbidity in the State in Bahia, Brazil: II — Analysis at the individual level

The present investigation was carried out on a sample of 840 children (5 to 16 years old) from ten small towns of the State of Bahia in northeastern Brazil. The objetive was to study, by using a cross sectional methodology, the evolution of schistosomiasis morbidity (hepatic and splenic enlargement) in children, and the role of the intensity of S. mansoni infection in this process. The children were analised in three age groups (5 to 8, to 12 and 13 to 16 years old) and classified as uninfected, mildly infected, moderately infected and heavily infected according to the number of eggs in the stool. In children aged 5 to 8 years, increasing egg counts were not associated with increasing frequencies of hepatic or splenic enlargement. In the 9 to 12 years old group and association was observed with the prevalence of hepatic enlargement, but not with the prevalence of spleen enlargement. In the oldest group, 13 to 16 years old, an association was observed with the prevalence of enlargement of both organs. It was evident that in this population schistosomiasis morbidity develops in the early period of life as a gradual process starting with liver enlargement and followed by spleen enlargement some years later. It was found that the intensity of infection has a fundamental role in this process, although there is a latent period of some years before clinical splenomegaly appears in moderate-heavily infected children. The Authors suggest that the prevalence of splenomegaly in the 13 to 16 years old group is a good measure of the community level of schistosomiasis morbidity and could be used to measure the impact of control programs.

Subcutaneous mucormycosis caused by Rhizopus oryzae: probable nosocomial acquired infection

The Authors present a case of subcutaneous mucormycosis occurring in a patient with clinical and biochemical evidence of diabetic ketoacidosis. The clinical, mycological and histopathological features are described, emphasizing the relevance of a rapid diagnosis in order to stablish early treatment. The clinical forms of mucormycosis and the main associated conditions are briefly reviewed as well as the most probable conditions which may lead to the enhanced susceptibility to infection in the diabetic patient in ketoacidosis. The recovery of Rhizopus oryzae from the air of the room of the patient suggests a nosocomial infection acquired through contamination of venous puncture site by air borne spores.

Experimental infection with Schistosoma mansoni of Biomphalaria straminea from different parts of the Northeast of Brazil

In the western part of the State of Bahia Biomphalaria straminea and B. glabrata both occur, but in the majority of cases they do not share the same habitat. In the State of Ceará, however, B. straminea is the sole snail host of Schistosoma mansoni. In this survey, no naturally infected B. straminea was found among snails collected from Bahia and Ceará, evidently because of the very low infection rates. The susceptibility of laboratory-reared specimens to infection with a Puerto Rican strain of S. mansoni was then tested experimentally. In general, the snails showed very low susceptibility. The infection rates were 1.1% among snails from Redenção (Ceará); 2.3% in those from Pentecoste (Ceará); 2.9% in snails from São Desidério (Bahia), while they were very high among an albino strain (NIH) of B. glabrata used as control. Another group of B. straminea from São Desidério was exposed to a Bahian strain of S. mansoni and the infection rate was still very low (3.6%) Apparently, the very low susceptibility of B. straminea, despite high snail density, is correlated with moderate infection rates with S. mansoni among humans, as shown by the results of stool examinations conducted by SUCAM in the municipalities of Redenção and Pentecoste, in Ceará.

Avaliação de software em open source para a gestão da Biblioteca UNL no Campus de Caparica

O presente trabalho parte da caracterização da Biblioteca UNL para desenvolver um estudo de avaliação dos principais Sistemas Integrados de Gestão de Bibliotecas (SIGB) em open source. Os SIGB são utilizados na automatização dos processos de trabalho das bibliotecas, através de diversos módulos funcionais e opções de configuração, e permitem a interoperabilidade através de normas e protocolos. O open source define-se como abordagem para o desenvolvimento e distribuição de software baseada no livre acesso ao código fonte, estando assim em oposição ao conceito de software proprietário. A Biblioteca UNL é caracterizada através da sua organização, dos seus espaços e recursos, dos seus processos de gestão documental e da infraestrutura tecnológica subjacente. O open source é abordado a partir da sua contextualização histórica, da organização dos seus projectos, das vantagens e inconvenientes para as instituições e do desenvolvimento e adopção de SIGB open source.