Interference cancellation in two-path successive relay system with network coding

This paper proposes a novel interference cancellation algorithm for the two-path successive relay system using network coding. The two-path successive relay scheme was proposed recently to achieve full date rate transmission with half-duplex relays. Due to the simultaneous data transmission at the relay and source nodes, the two-path relay suffers from the so-called inter-relay interference (IRI) which may significantly degrade the system performance. In this paper, we propose to use the network coding to remove the IRI such that the interference is first encoded with the network coding at the relay nodes and later removed at the destination. The network coding has low complexity and can well suppress the IRI. Numerical simulations show that the proposed algorithm has better performance than existing approaches.

Differential effects of internal and external factors on the development of vocabulary, tense morphology and morpho-syntax in successive bilingual children

The present study investigates the effects of child internal (age/time) and child external/environmental factors on the development of a wide range of language domains in successive bilingual (L2) Turkish-English children of homogeneously low SES. Forty-three L2 children were tested on standardized assessments examining the acquisition of vocabulary and morpho-syntax. The L2 children exhibited a differential acquisition of the various domains: they were better on the general comprehension of grammar and tense morphology and less accurate on the acquisition of vocabulary and (complex) morpho-syntax. Profile effects were confirmed by the differential effects of internal and external factors on the language domains. The development of vocabulary and complex syntax were affected by internal and external factors, whereas external factors had no contribution to the development of tense morphology. These results are discussed in light of previous studies on the impact of internal and external factors in child L2 acquisition.

Stated attribute non-attendance in successive choice experiments

Attribute non-attendance in choice experiments affects WTP estimates and therefore the validity of the method. A recent strand of literature uses attenuated estimates of marginal utilities of ignored attributes. Following this approach, we propose a generalisation of the mixed logit model whereby the distribution of marginal utility coefficients of a stated non-attender has a potentially lower mean and lower variance than those of a stated attender. Model comparison shows that our shrinkage approach fits the data better and produces more reliable WTP estimates. We further find that while reliability of stated attribute non-attendance increases in successive choice experiments, it does not increase when respondents report having ignored the same attribute twice.

Isolation, chemical composition and anti-inflammatory activity of Copaifera langsdorffii desf. fruit peels essential oil according to successive hydrodistillations

In this study, the isolation and characterization of chemical composition of C. langsdorffii (copaiba) fruit peel volatile oil from Alfenas - MG was carried out according to successive hydrodistillations, likewise the anti-inflammatory activity was evaluated by rat paw edema model. The chemical composition of the oil was determined by GC-MS analysis. The major components were (E)-caryophyllene, germacrene B, 1,5-epoxysalvial-4(14)-ene, caryophyllene oxide and isospathulenol. The inflammatory process was inhibited in 39 +/- 6 % (p<0.05, Tukey-Kramer) by one sample of essential oil. The C. langsdorffii fruit peel is a rich source of essential oil (3.8% w/w), and due to potential industrial interest of its components this ecotype presents feasible crop seeking productivity and it could constitutes in a good alternative to the sustainable use of this specie.

Behavioural and seminal characteristics of Santa Ines rams subjected to successive semen collections in the Amazonian region

The objective of this study was to evaluate the reproductive performance of Santa Ines rams subjected to successive semen collections in an Amazonian climate. Four rams were subjected to successive ejaculations during a maximum period of three hours. This procedure was repeated three times at 15-day intervals. Sexual and behavioural (libido) and andrological (testicular and seminal) assessments were performed. A total of 81 ejaculates were collected. Libido and semen vigour, volume, appearance and concentration decreased as the ejaculation frequency increased (P<0.05) and sperm motility showed a decreasing trend (P=0.06). The seminal pH increased over the sequence of collections (P<0.05). The only significant differences observed between individual rams were the variable scrotal circumference and the percentages of live sperm and sperm abnormalities (P<0.05). All the parameters of the first ejaculation were within the normal range for this species, which suggests that the local climatic conditions (high temperature and humidity) did not affect the behavioural, testicular or seminal parameters of experimental rams. Our findings indicate that the reproductive performance of Santa Ines rams could be affected by the intensification of ejaculation frequency; however, individual male variation needs to be taken into consideration.

Impact of successive sugarcane harvests and trash management practices on soil microbiological properties

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

STEM ANATOMY and DEVELOPMENT of SUCCESSIVE CAMBIA IN THE NEOTROPICAL LIANA SECURIDACA RIVINIFOLIA (POLYGALACEAE)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Microsporogenesis is simultaneous in the early-divergent grass Streptochaeta, but successive in the closest grass relative, Ecdeiocolea

Simultaneous microsporogenesis is described for the first time in a grass, Streptochaeta spicata Schrad., a tropical Brazilian species that belongs in the early-divergent subfamily Anomochlooideae. Microsporogenesis is successive in all other Poaceae examined so far, and most other members of the order Poales, to which grasses belong. The only other reports of simultaneous microsporogenesis in Poales are in Rapateaceae and some members of the cyperid clade (Juncaceae, Cyperaceae, Prionium and Thurnia). Among the graminids, Ecdeiocolea (the putative closest relative to Poaceae) is successive, as are Joinvillea, Flagellaria and all other Poaceae, indicating that the simultaneous condition is autapomorphic in Streptochaeta, though Anomochloa has yet to be examined. Anther wall development in Streptochaeta is of the reduced type, as also in another early-divergent grass Pharus, though most other Poales, including most grasses, have the monocot type. In Streptochaeta, as in Pharus, the endothecium lacks thickenings, unlike other grasses that have a persistent endothecium with thickenings. The centrifixed anthers and nonplumose stigmas of Streptochaeta suggest entomophily.

Caffeine effect on mortality and oviposition in successive generations of Aedes aegypti

OBJETIVO: Experimentos anteriores mostraram que a cafeína bloqueia o desenvolvimento de Aedes aegypti (Diptera, Culicidae) na fase larval, inibindo conseqüentemente a produção de adultos. O objetivo do estudo foi obter dados que pudessem sugerir desenvolvimento de resistência dos mosquitos à cafeína. MÉTODOS: Foi avaliada a produção de adultos em gerações sucessivas, a partir de ovos produzidos na geração anterior e a taxa de oviposição em cada geração, utilizando meios contendo cafeína a 200 e 500 µg/ml e água de torneira proveniente de poço artesiano como controle. Os experimentos foram conduzidos em São José do Rio Preto, entre 2002 e 2005. Nos testes estatísticos foram utilizados a análise exploratória de dados e algoritmos de alisamento. RESULTADOS: Ocorreu redução crescente da produção de adultos, nas duas concentrações, ao longo das gerações, mas apenas no experimento a 200 µg/ml os dados foram estatisticamente significantes. Quanto à oviposição, a análise dos números mostra redução crescente e acentuada na média de ovos por fêmea, no experimento tratado. CONCLUSÕES: Não houve evidência de resistência ao longo das gerações devido ao tratamento com cafeína. Os resultados encontrados podem reforçar a indicação da cafeína como uma alternativa aos principais agentes de controle do Ae. aegypti atualmente usados, contra os quais os mosquitos têm desenvolvido resistência.

Development of successive cambia and structure of wood in Gallesia integrifolia (Spreng.) Harms (Phytolaccaceae)

Stem diameter in Gallesia integrifolia (Spreng.) Harms (Phytolaccaceae) increases by forming concentric rings of xylem alternating with phloem, which show frequent anastomoses. After a period of primary growth and the formation of first (normal) ring of vascular cambium, further successive rings are initiated outside this cambium. The second ring of cambium originates from the pericycle parenchyma located between the proto-phloem, and the pericycle fibres. Each cambium produces centripetally secondary xylem and centrifugally secondary phloem. Differentiation of xylem precedes that of phloem and the first elements formed are always xylem fibres. Structurally, the vascular cylinder is composed by successive rings of secondary xylem and phloem. These rings are separated by wide bands of conjunctive parenchyma tissue. Presence of collateral vascular bundles with irregular orientation is observed in the region of anastomoses of two or more bands of conjunctive tissue. These bundles are surrounded by isodiametric, lignified and thick-walled cells. In some of the cambial rings, occurrence of polycentric rays was also noticed; these rays are tall, and characterized by the presence of meristematic regions that differentiated into thick-walled elements of secondary xylem. Origin and development of the successive cambia and the structure of xylem are discussed.

Chromosomal imbalances in successive moments of human bladder urothelial carcinoma

Objective: To understand developmental characteristics of urinary bladder carcinomas (UBC) by evaluating genomic alterations and p53 protein expression in primary tumors, their recurrences, and in the morphologically normal urothelium of UBC patients. Methods: Tumors and their respective recurrences, six low-grade and five high-grade cases, provided 19 samples that were submitted to laser microdissection capture followed by high resolution comparative genomic hybridization (HR-CGH). HR-CGH profiles went through two different analyses-all tumors combined or classified according to their respective histologic grades. In a supplementary analysis, 124 primary urothelial tumors, their recurrences, and normal urothelium biopsied during the period between tumor surgical resection and recurrence, were submitted to immunohistochemical analyses of the p53 protein. During the follow-up of at least 21 patients, urinary bladder washes citologically negative for neoplastic cells were submitted to fluorescence in situ hybridization (FISH) to detect copy number alterations in centromeres 7, 17, and 9p21 region. Results and Conclusions: HR-CGH indicated high frequencies (80%) of gains in 11p12 and losses in 16p12, in line with suggestions that these chromosome regions contain genes critical for urinary bladder carcinogenesis. Within a same patient, tumors and their respective recurrences showed common genomic losses and gains, which implies that the genomic profile acquired by primary tumors was relatively stable. There were exclusive genomic alterations in low and in high grade tumors. Genes mapped in these regions should be investigated on their involvement in the urinary bladder carcinogenesis. Successive tumors from same patient did not present similar levels of protein p53 expression; however, when cases were grouped according to tumor histologic grades, p53 expression was directly proportional to tumor grades. Biopsies taken during the follow-up of patients with history of previously resected UBC revealed that 5/15 patients with no histologic alterations had more than 25% of urothelial cells expressing the p53 protein, suggesting that the apparently normal urothelium was genomically unstable. No numerical alterations of the chromosomes 7, 17, and 9p21 region were found by FISH during the periods free-of-neoplasia. Our data are informative for further studies to better understand urinary bladder urothelial carcinogenesis. © 2013 Elsevier Inc.

Stem anatomy and development of successive cambia in Hebanthe eriantha (Poir.) Pedersen: A neotropical climbing species of the Amaranthaceae

Hebanthe eriantha (Poir.) Pedersen, a climbing species of the Amaranthaceae increases in stem thickness by forming successive cambia. The family is dominated by herbaceous species and is constantly under discussion due to its disputed nature of the meristem. In the young stem small alternate segments of vascular cambium cease to divide and new arc of cambium initiates outside to it. The newly formed arcs connect with pre-existing alternate segments of cambium to complete the ring. On the contrary, in thick stems, instead of small segments, complete ring of cambium is replaced by new one. These new alternate segments/cambia originate from the parenchyma cells located outside to the phloem produced by previous cambium. Cambium is storied and exclusively composed of fusiform initials while ray cells remain absent at least in the early part of the secondary growth. However, large heterocellular rays are observed in 15-mm diameter stems but their frequency is much lower. In some of the rays, ray cells become meristematic and differentiate into radially arranged xylem and phloem elements. In fully grown plants, stems are composed of several successive rings of secondary xylem alternating with secondary phloem. Secondary xylem is diffuse-porous and composed of vessels, fibres, axial parenchyma while exceptionally large rays are observed only in the outermost regions of thick stems. Vessel diameter increases progressively from the centre towards the periphery of stems. Although the origin of successive cambia and composition of secondary xylem of H. eriantha remains similar to other herbaceous members of Amaranthaceae, the occurrence of relatively wider and thick-walled vessels and large rays in fully grown plants is characteristic to climbing habit. © 2013 Springer-Verlag Wien.

Evaluation of sperm quality in successive regular collections from captive black-and-gold howler monkeys (Alouatta caraya)

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