Auctions of identical objects with single-unit demands : a survey

The theory of auctions of a single object generalizes to a situation where identical objects are sold either sequentially or simultaneously but individuais can only buy one object. In this context, I will present a survey of the main results regarding the ranking of auctions based on revenue, bidding behaviour, effects of entry fees and reserve prices, and other strategic issues.

Síndromes de polinização ocorrentes em uma área de Mata Atlântica, Paraíba, Brasil

ARAUJO, Afranio Cesar de et al. Síndromes de polinização ocorrentes em uma área de Mata Atlântica, Paraíba, Brasil. Biotemas, Florianopolis, v. 4, n. 22, p.83-94, dez. 2009. Disponível em: . Acesso em: 04 out. 2010.

An investigation of Hebbian phase sequences as assembly graphs

Hebb proposed that synapses between neurons that fire synchronously are strengthened, forming cell assemblies and phase sequences. The former, on a shorter scale, are ensembles of synchronized cells that function transiently as a closed processing system; the latter, on a larger scale, correspond to the sequential activation of cell assemblies able to represent percepts and behaviors. Nowadays, the recording of large neuronal populations allows for the detection of multiple cell assemblies. Within Hebb's theory, the next logical step is the analysis of phase sequences. Here we detected phase sequences as consecutive assembly activation patterns, and then analyzed their graph attributes in relation to behavior. We investigated action potentials recorded from the adult rat hippocampus and neocortex before, during and after novel object exploration (experimental periods). Within assembly graphs, each assembly corresponded to a node, and each edge corresponded to the temporal sequence of consecutive node activations. The sum of all assembly activations was proportional to firing rates, but the activity of individual assemblies was not. Assembly repertoire was stable across experimental periods, suggesting that novel experience does not create new assemblies in the adult rat. Assembly graph attributes, on the other hand, varied significantly across behavioral states and experimental periods, and were separable enough to correctly classify experimental periods (Naïve Bayes classifier; maximum AUROCs ranging from 0.55 to 0.99) and behavioral states (waking, slow wave sleep, and rapid eye movement sleep; maximum AUROCs ranging from 0.64 to 0.98). Our findings agree with Hebb's view that assemblies correspond to primitive building blocks of representation, nearly unchanged in the adult, while phase sequences are labile across behavioral states and change after novel experience. The results are compatible with a role for phase sequences in behavior and cognition.

Anaerobic bio-digestion of concentrate obtained in the process of ultra filtration of effluents from tilapia processing unit

The objective of the present study was to evaluate the efficiency of the process of biodigestion of the protein concentrate resulting from the ultrafiltration of the effluent from a slaughterhouse freezer of Nile tilapia. Bench digesters were used with excrements and water (control) in comparison with a mixture of cattle manure and effluent from the stages of filleting and bleeding of tilapias. The effluent obtained in the continuous process (bleeding + filleting) was the one with highest accumulated population from the 37th day, as well as greatest daily production. Gases composition did not differ between the protein concentrates, but the gas obtained with the use of the effluent from the filleting stage presented highest methane gas average (78.05%) in comparison with those obtained in the bleeding stage (69.95%) and in the continuous process (70.02%) or by the control method (68.59%).

Dificuldades e/ou facilidades vivenciadas pelos profissionais que compõem a Estratégia de Saúde da Família

Descriptive and quantitative study, with the objective of review the positive and negative aspects experienced by professionals working in the Family Health Strategy (ESF) of Ceará-Mirim town, at Rio Grande do Norte state. The population included 190 healthcare professionals that integrate the family healthcare staff and the data-collection occurred in a meeting at their workplace, with the implementation of a questionnaire. Results were organized in Microsoft Excel spreadsheet software, with descriptive statistical analysis in tables, graphs and tables through frequencies, averages values and standard deviations. There is a predominance of females (n = 137) and higher rates in almost all professions, and higher average age (38.9%, SD = 7.8) and income wage (average = 10) in the medical category. Regarding the more developed activities, for physicians and nurses are the healthcare actions in the Unit, the oral hygiene for dentists, the immunization for auxiliary nurses (Aux-N), educational meeting for the dental office assistants (ACD), and home visitations to community-based health workers (ACS). About the easiness of work, 93.2% said to be presence of professionals with a personal profile in public healthcare; about the difficulties, 86.8% of professionals cited the unavailability of material, followed by salary range reported by nurses (80.9% ), dentists (80.0%), physicians (73.3%), ACS (83.1%), and Aux-N (90.5%). In relation to working conditions, the unavailability of materials was the most mentioned, with the exception of dentists who reported improvement in wages. We still identify among these difficulties: the drugs availability regarded as first grade obstacle by ACS and physicians, the type of contracts in second grade cited by the ACD and dentists and, in third grade, the salary range cited by dentists and auxiliary nurses. It is concluded that the difficulties and easiness faced by ESF professionals are divergent among themselves. For physicians and nurses, whose healthcare actions become directed to specific groups, the individual and the family, their difficulties relate to the unavailability of materials. For dentists, whose actions more quoted were topical application of fluoride and supervised toothbrush, their greatest difficulty is the salary range. As to the Aux-N, ACD and ACS, for all of them the unavailability of materials has hindered the implementation of their activities in ESF

Custo-efetividade da terapia compressiva no processo de cicatrização de úlceras venosas

Analytical study of therapeutic nonrandomized intervention type, intra-group controlled, with the aim of analyzing the cost-effectiveness of compression therapy with manipulated Unna boot in relation to conventional therapy in the healing of venous ulcers (VU) of patients treated in ambulatory clinic. The study population was composed by patients with VU treated by angiologists in Surgical Clinic Ambulatory of the Onofre Lopes University Hospital (HUOL) with a sample of 18 patients. It obtained the assent of the HUOL Ethics in Research Committee (Protocol 276/09). Data collection was performed over a period of four months by the own master's student and 34 nursing students, through the application of the research instrument in the admission of patients to the study and in the ten subsequent evaluations, performed at the time of changing Unna boot, weekly, for a maximum period of 10 weeks. The data were analyzed with SPSS 15.0 software, using descriptive and inferential statistics, and presented as tables, charts and graphs. Among those surveyed, prevailed: females, mean age 57.6 years, low education and income levels, most retired, unemployed or off work, with the standing position more than six hours per day and up to eight hours daily of domestic or occupational activities. In health status profile of respondents there were predominantly sleep, rest and inadequate elevation of the lower limbs, no smoking and/or alcohol use, presence of hypertension and no use of drugs. Most presented the first VU for over 10 years, recurrences, present VU for more than five years, involvement of left leg, in malleolar and / or distal leg region, mild edema, hyperpigmentation, lipodermatosclerosis, telangiectasies, reticular and varicose veins, mild pain, serous exudate in moderate quantity, small lesions (up to 50cm2), with predominance of granulation tissue and / or epithelialization and demarcated, elevated and irregular borders, with crusts and macerated. Most patients reported that in the 10 weeks prior to admission, made bandages at home and / or Basic Health Unit and / or ambulatory, with nursing aides or technicians, daily, and on weekends or holidays, performed by patients themselves, using healing ointment on the lesion, being observed granulation / epithelialization and increase in VU prevalent in the 10 weeks of traditional treatment. After follow up with manipulated Unna boot, was observed a decrease of lesions in all study patients, with complete healing in 27.8% of those between 1 and 5 weeks of treatment, with satisfactory evolution of the lesions, pain and ankle and calf circumferences, and unsatisfactory development of the borders of ulcers, edema, sleep, rest and elevation of the lower limbs, especially in more chronic patients. Furthermore, patients who achieved total healing and exhibited the greatest percentage reduction of lesions had a higher number of wound healing factors (ρ = 0.01 and ρ = 0.027, respectively). The manipulated Unna boot showed better results in those patients with shorter duration of injury, leading them to a satisfactory outcome within a short period of treatment. After the cost-effectiveness analysis, we conclude that the manipulated Unna boot is more effective than conventional therapy in the healing process of VU and is more cost-effective in patients with shorter lesions (ρ = 0.001), shorter treatment (ρ = 0.000) and greater number of wound healing factors (ρ = 0.005).

Candida parapsilosis complex water isolates from a haemodialysis unit: biofilm production and in vitro evaluation of the use of clinical antifungals

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atenção à saúde da pessoa idosa na estratégia saúde da família no município de Santo Antônio/RN: um estudo de caso

According to demographic estimates, by the year 2025 Brazil will be the sixth country in the world in number of elderly. For this reason, it is a purpose of public policies to help people to reach that age being healthier. The current health care model of health surveillance through the Family Health Strategy (EFS, in portuguese) is configured as a gateway into the care of the elderly in the Unified Health System (SUS, in portuguese). It is also an area of development of practices to promote health, prevention and control of chronic nondegenerative diseases. The aim of this study was to analyze the health care of the elderly provided by ESF professionals for the achievement of a full care. The study is descriptive case study with a quantitative approach, performed in the city of Santo Antônio/RN. The population included all health professionals, who are FHS members of the city that agreed to participate of the survey, a total of 80 professionals. Data were collected using a structured questionnaire, having mostly closed questions and divided into two parts: one containing sociodemographic information of health professionals and vocational training and the other, the activities carried on by the professionals in senior care, being analyzed from a database tabulated in a spreadsheet and discussed according to the descriptive statistics in tables, graphs and charts using frequencies, medians and values of central tendency. It was verified a predominance of professionals who finished highschool, mostly female, aged from 30 to 34 years old, with training completed in the last 10 years, without being graduated in the field of geriatrics or gerontology and mostly without training in gerontology. Family members and caregivers were the components of the social support network most identified by the professionals (66.3%).The elderly access to the Family Health Basic Unit was considered by83.8% of professionals as the most important factor that interferes in the activities of health care of the elderly. Considering the inclusion of the family in care: 98.8% of professionals consider the family as one of the goals of care, but 82.5% assist the family to know their role and participate in the care of the elderly, emphasizing that no professional makes use of tools for evaluating the functionality of the family. Regarding the actions taken to assist the elderly, 91.25% have home visits program to the elderly, 88.75% use the host program; 77.5% know the habits of life, cultural, ethical and religious values of the elderly, their families and their community ;51.25% complement the activities through intersectoral actions, 50%participate in groups of living with the elderly; 33.75% keeps track and maintain updated the health information of the elderly; 11.25% of the professionals perform the Single Therapy Planning (PTS, in portuguese) and few implement the actions to promote health according to PTS; there is a deficit in the number of professional categories in the identification and monitoring of the frail older people in their households. It is concluded that the health care of the elderly developed by ESF professionals differs among the professional categories. It was identified weaknesses in the promotion of an active and healthy aging and also in the establishment of an integrated and full care of the elderly. It is recommended the adoption of permanent educational activities by the City Management, initially for ESF professionals in the the perspective of the guidelines of the National Policy of Health Care for the Elderly and later to the other professionals that are part of the health care network of the elderly, at all levels of care in the city for the development of strategies and practices that promote the improvement of the quality of healthcare for the elderly, expecting concrete and effective results in terms of promoting health within Brazilian reality

EFFICIENCY of PNEUMATIC and HORIZONTAL PERFORATED DISK METER MECHANISM IN CORN NO-TILLAGE SEEDERS IN SOIL WITH DIFFERENT MOBILIZATION REPORTS

This work objectified to evaluate the efficiency of two meter mechanism of corn seeds when submitted to different forward speed and soil management system during the non-tillage seeding. It was used a factorial design in randomized blocks. The factors whose effects were examined were related to the seeders with pneumatic and horizontal disk meter mechanisms for the distribution of the seeds, to the set tractor-seeder forward speeds (4.4; 8.0 and 9.8 km h(-1)), and to the soil management system considering the corn no-tillage seeding over minimum tillage with chisel plow and the no-tillage system for the seeding of oat culture (Avena strigosa Schreb). It was verified that the forward speed didn't influence the initial and final stands of plants but it interfered in the regularity of longitudinal distribution of plants. The smallest speed provided the largest percentile of normal spacing between plants. The pneumatic meter mechanism presented better performance than the horizontal disk perforated in the longitudinal distribution of plants. About corn productivity aspect it's indifferent the recommendation of use for pneumatic and perforated horizontal disk meter mechanism of seeds.

Detection of mixed microbial biofilms on central venous catheters removed from Intensive care Unit Patients

Cateteres venosos centrais inseridos em pacientes internados em unidade de terapia intensiva foram avaliados por métodos microbiológicos (cultura semi-quantitativa) e microscopia eletrônica de varredura a fim de detectar adesão microbiana e correlacionar com a cultura de sangue. Durante o período de estudo, foram avaliados 59 pacientes com cateter venoso central. A idade dos pacientes, sexo, sítio de inserção e tempo de permanência do cateter foram anotados. O cateter era de poliuretano não tunelizado e de único lúmen. O sangue para cultura foi coletado no momento da remoção do cateter. de 63 pontas de cateteres, 30 (47,6%) foram colonizadas e a infecção encontrada em 5 (23,8%) cateteres. A infecção foi mais prevalente em 26 pacientes (41,3%) com cateteres inseridos em veia subclávia do que nos 3 (3,2%) inseridos em veia jugular. A infecção foi observada com mais freqüência em cateteres com tempo de permanência maior do que sete dias. Os microrganismos isolados incluíram 32 estafilococos coagulase-negativa (29,7%), 61 bactérias Gram-negativas (52,9%), 9 estafilcocos coagulase-positiva (8,3%) e 3 leveduras (2,7%). Como agentes causais de infecções em unidade de terapia intensiva foram isolados E. aerogenes, P. aeruginosa, A. baumannii. Os antimicrobianos com maior atividade in vitro contra as bactérias Gram-negativas foram o imipenem e contra as Gram-positivas vancomicina, cefepime, penicilina, rifampicina e tetraciclina. As análises por microscopia eletrônica de varredura revelaram biofilmes sobre a superfície de todos os cateteres examinados.

Vortices in a mesoscopic superconducting disk of variable thickness

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Photoinduced hole-transfer in semiconducting polymer/low-bandgap cyanine dye blends: evidence for unit charge separation quantum yield

Power-conversion efficiencies of organic heterojunction solar cells can be increased by using semiconducting donor-acceptor materials with complementary absorption spectra extending to the near-infrared region. Here, we used continuous wave fluorescence and absorption, as well as nanosecond transient absorption spectroscopy to study the initial charge transfer step for blends of a donor poly(p-phenylenevinylene) derivative and low-band gap cyanine dyes serving as electron acceptors. Electron transfer is the dominant relaxation process after photoexcitation of the donor. Hole transfer after cyanine photoexcitation occurs with an efficiency close to unity up to dye concentrations of similar to 30 wt%. Cyanines present an efficient self-quenching mechanism of their fluorescence, and for higher dye loadings in the blend, or pure cyanine films, this process effectively reduces the hole transfer. Comparison between dye emission in an inert polystyrene matrix and the donor matrix allowed us to separate the influence of self-quenching and charge transfer mechanisms. Favorable photovoltaic bilayer performance, including high open-circuit voltages of similar to 1 V confirmed the results from optical experiments. The characteristics of solar cells using different dyes also highlighted the need for balanced adjustment of the energy levels and their offsets at the heterojunction when using low-bandgap materials, and accentuated important effects of interface interactions and solid-state packing on charge generation and transport.

Vortex state in a mesoscopic flat disk with rough surface

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mean motion resonances and the stability of a circumbinary disk in a triple stellar system

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Signal-flow graphs: Direct method of reduction and MATLAB implementation

Block diagrams and signal-flow graphs are used to represent and to obtain the transfer function of interconnected systems. The reduction of signal-flow graphs is considered simpler than the reduction of block diagrams for systems with complex interrelationships. Signal-flow graphs reduction can be made without graphic manipulations of diagrams, and it is attractive for a computational implementation. In this paper the authors propose a computational method for direct reduction of signal-flow graphs. This method uses results presented in this paper about the calculation of literal determinants without symbolic mathematics tools. The Cramer's rule is applied for the solution of a set of linear equations, A program in MATLAB language for reduction of signal-flow graphs with the proposed method is presented.