bluuebunny/crossref_metadata_2025 huggingface dataset:
Dissection of a DNA-damage-induced transcriptional network using a combination of microarrays, RNA interference and computational promoter analysis
Authors: Elkon Ran , Rashi-Elkeles Sharon , Lerenthal Yaniv , Linhart Chaim , Tenne Tamar , Amariglio Ninette , Rechavi Gideon , Shamir Ron , Shiloh Yosef
Published: April 2005

Background

Gene-expression microarrays and RNA interferences (RNAi) are among the most prominent techniques in functional genomics. The combination of the two holds promise for systematic, large-scale dissection of transcriptional networks. Recent studies, however, raise the concern that nonspecific responses to small interfering RNAs (siRNAs) might obscure the consequences of silencing the gene of interest, throwing into question the ability of this experimental strategy to achieve precise network dissections.

Results

We used microarrays and RNAi to dissect a transcriptional network induced by DNA damage in a human cellular system. We recorded expression profiles with and without exposure of the cells to a radiomimetic drug that induces DNA double-strand breaks (DSBs). Profiles were measured in control cells and in cells knocked-down for the Rel-A subunit of NFκB and for p53, two pivotal stress-induced transcription factors, and for the protein kinase ATM, the major transducer of the cellular responses to DSBs. We observed that NFκB and p53 mediated most of the damage-induced gene activation; that they controlled the activation of largely disjoint sets of genes; and that ATM was required for the activation of both pathways. Applying computational promoter analysis, we demonstrated that the dissection of the network into ATM/NFκB and ATM/p53-mediated arms was highly accurate.

Conclusions

Our results demonstrate that the combined experimental strategy of expression arrays and RNAi is indeed a powerful method for the dissection of complex transcriptional networks, and that computational promoter analysis can provide a strong complementary means for assessing the accuracy of this dissection.
Limit theorems for stationary tessellations with random inner cell structures
Authors: Heinrich Lothar , Schmidt Hendrik , Schmidt Volker
Published: April 2005

We consider stationary and ergodic tessellations X = Ξnn≥1 in Rd, where X is observed in a bounded and convex sampling window Wp ⊂ Rd. It is assumed that the cells Ξn of X possess random inner structures, examples of which include point patterns, fibre systems, and tessellations. These inner cell structures are generated, both independently of each other and independently of the tessellation X, by generic stationary random sets that are related to a stationary random vector measure J0 acting on Rd. In particular, we study the asymptotic behaviour of a multivariate random functional, which is determined both by X and by the individual cell structures contained in Wp, as Wp ↑ Rd. It turns out that this functional provides an unbiased estimator for the intensity vector associated with J0. Furthermore, under natural restrictions, strong laws of large numbers and a multivariate central limit theorem of the normalized functional are proven. Finally, we discuss in detail some numerical examples and applications, for which the inner structures of the cells of X are induced by iterated Poisson-type tessellations.
Generalised shot noise Cox processes
Authors: Møller Jesper , Torrisi Giovanni Luca
Published: April 2005

We introduce a class of Cox cluster processes called generalised shot noise Cox processes (GSNCPs), which extends the definition of shot noise Cox processes (SNCPs) in two directions: the point process that drives the shot noise is not necessarily Poisson, and the kernel of the shot noise can be random. Thereby, a very large class of models for aggregated or clustered point patterns is obtained. Due to the structure of GSNCPs, a number of useful results can be established. We focus first on deriving summary statistics for GSNCPs and, second, on how to simulate such processes. In particular, results on first- and second-order moment measures, reduced Palm distributions, theJ-function, simulation with or without edge effects, and conditional simulation of the intensity function driving a GSNCP are given. Our results are exemplified in important special cases of GSNCPs, and we discuss their relation to the corresponding results for SNCPs.
On the fundamental theorem of card counting, with application to the game of trente et quarante
Authors: Ethier S. N. , Levin David A.
Published: April 2005

A simplified proof of Thorp and Walden's fundamental theorem of card counting is presented, and a corresponding central limit theorem is established. Results are applied to the casino game of trente et quarante, which was studied by Poisson and De Morgan.
Reflected backward stochastic differential equations under monotonicity and general increasing growth conditions
Authors: Lepeltier J.-P. , Matoussi A. , Xu M.
Published: April 2005

We prove the existence and uniqueness of the solution to certain reflected backward stochastic differential equations (RBSDEs) with one continuous barrier and deterministic terminal time, under monotonicity, and general increasing growth conditions on the associated coefficient. As an application, we obtain, in some constraint cases, the price of an American contingent claim as the unique solution of such an RBSDE.
A queue with semiperiodic traffic
Authors: Alvarez Juan , Hajek Bruce
Published: April 2005

In this paper, we analyze the diffusion limit of a discrete-time queueing system with constant service rate and connections that randomly enter and depart from the system. Each connection generates periodic traffic while it is active, and a connection's lifetime has finite mean. This can model a time division multiple access system with constant bit-rate connections. The diffusion scaling retains semiperiodic behavior in the limit, allowing for both short-time analysis (within one frame) and long-time analysis (over multiple frames). Weak convergence of the cumulative arrival process and the stationary buffer-length distribution is proved. It is shown that the limit of the cumulative arrival process can be viewed as a discrete-time stationary-increment Gaussian process interpolated by Brownian bridges. We present bounds on the overflow probability of the limit queueing process as functions of the arrival rate and the connection lifetime distribution. Also, numerical and simulation results are presented for geometrically distributed connection lifetimes.
Generalized product-form stationary distributions for Markov chains in random environments with queueing applications
Authors: Economou Antonis
Published: April 2005

Consider a continuous-time Markov chain evolving in a random environment. We study certain forms of interaction between the process of interest and the environmental process, under which the stationary joint distribution is tractable. Moreover, we obtain necessary and sufficient conditions for a product-form stationary distribution. A number of examples that illustrate the applicability of our results in queueing and population growth models are also included.
On the number of vertices with a given degree in a Galton-Watson tree
Authors: Minami Nariyuki
Published: April 2005

Let Yk(ω) (k ≥ 0) be the number of vertices of a Galton-Watson tree ω that have k children, so that Z(ω) := ∑k≥0Yk(ω) is the total progeny of ω. In this paper, we will prove various statistical properties of Z and Yk. We first show, under a mild condition, an asymptotic expansion of P(Z = n) as n → ∞, improving the theorem of Otter (1949). Next, we show that Yk(ω) := ∑j=0kYj(ω) is the total progeny of a new Galton-Watson tree that is hidden in the original tree ω. We then proceed to study the joint probability distribution of Z and Ykk, and show that, as n → ∞, Yk/nk is asymptotically Gaussian under the conditional distribution P(· | Z = n).
Phase transitions and duality properties of a successional model
Authors: Lanchier Nicolas
Published: April 2005

The first purpose of this article is to study the phase transitions of a new interacting particle system. We consider two types of particle, each of which gives birth to particles of the same type as the parent. Particles of the second type can die, whereas those of the first type mutate into the second type. We prove that the three possible outcomes of the process, that is, extinction, survival of the type-2s, or coexistence, may each occur, depending on the selected parameters. Our second, and main, objective, however, is to investigate the duality properties of the process; the corresponding dual process exhibits a structure somewhat different to that of well-known particle systems.
Loss of the extraembryonic ectoderm inElf5mutants leads to defects in embryonic patterning
Authors: Donnison Martyn , Beaton Angela , Davey Helen W. , Broadhurst Ric , L'Huillier Phil , Pfeffer Peter L.
Published: April 2005

The extraembryonic ectoderm (ExE) is essential for mammalian placental formation and survival of the embryo in utero. We have obtained a mouse model lacking the ExE, by targeted deletion of the transcription factor Elf5. Although Elf5 mutant embryos implant and form an ectoplacental cone, no trophoblast stem (TS) cells can be derived, indicating that the absence of ExE is a result of the lack of TS cell maintenance. Embryos without ExE tissue are able to form the anterior visceral endoderm but fail to undergo gastrulation, demonstrating an essential role for the ExE in embryonic patterning during a defined window of development.
Production ofgurkenin the nurse cells is sufficient for axis determination in theDrosophilaoocyte
Authors: Cáceres Lucía , Nilson Laura A.
Published: April 2005

The asymmetric localization of gurken mRNA and protein in the developing Drosophila oocyte defines both the anteroposterior and dorsoventral axes of the future embryo. Understanding the origin of these asymmetries requires knowledge of the source of gurken transcripts. During oogenesis most transcripts in the oocyte are produced by the associated nurse cells, but it has been proposed that gurken is an exceptional oocyte-derived transcript. Using a novel application of a standard mitotic recombination technique, we generated mosaic egg chambers in which the nurse cells, but not the oocyte, could produce gurken. Gurken was properly localized in these mosaics and oocyte axial polarity was established normally,indicating that the nurse cells synthesize gurken and that their contribution is sufficient for Gurken function. Our data demonstrate the existence of a mechanism for transport of gurken from the nurse cells and its subsequent localization within the oocyte.
The t(8;21) translocation converts AML1 into a constitutive transcriptional repressor
Authors: Wildonger Jill , Mann Richard S.
Published: April 2005

The human translocation (t8;21) is associated with ∼12% of the cases of acute myelogenous leukemia. Two genes, AML1 and ETO, are fused together at the translocation breakpoint, resulting in the expression of a chimeric protein called AML1-ETO. AML1-ETO is thought to interfere with normal AML1 function, although the mechanism by which it does so is unclear. Here, we have used Drosophila genetics to investigate two models of AML1-ETO function. In the first model, AML1-ETO is a constitutive transcriptional repressor of AML1 target genes, regardless of whether they are normally activated or repressed by AML1. In the second model, AML1-ETO dominantly interferes with AML1 activity by, for example, competing for a common co-factor. To discriminate between these models, the effects of expressing AML1-ETO were characterized and compared with loss-of-function phenotypes of lozenge (lz), an AML1 homolog expressed during Drosophila eye development. We also present results of genetic interaction experiments with AML1 co-factors that are not consistent with AML1-ETO behaving as a dominant-negative factor. Instead, our data suggest that AML1-ETO acts as a constitutive transcriptional repressor.
Visualization of late-cycle phenomena in a direct injection spark ignition engine
Authors: Strand T E , Rothamer D A , Ghandhi J B
Published: April 2005

Planar laser-induced fluorescence measurements of 3-pentanone doped into the fuel and the hydroxyl (OH) radical were separately performed in a direct injection spark ignition engine operating unthrottled at 600 r/min with an overall fuel-air equivalence ratio φ of 0.3. It was found that the premixed flame, identified by OH fluorescence, did not propagate fully to the outermost edge of the combustion chamber regardless of image timing. Further, late in the cycle after the heat release had completed, fuel fluorescence was identified at the combustion chamber periphery. The fuel concentration at these late times was found to be lean, with little fuel at φ > 0.5. These findings strongly suggest that the flame has quenched at the edge of the fuel cloud, confirming a long-held belief about stratified combustion. A series of additional experiments were performed to examine the factors controlling the observed quenching phenomenon. Changes in the end gas conditions resulting from advanced combustion phasing were not sufficient to alleviate the existence of late-cycle fuel fluorescence. Throttling the intake to 69 kPa while maintaining the same mass of fuel injected resulted in complete flame propagation in the investigated field of view, as evidenced by the OH fluorescence, and late-cycle fuel fluorescence was not present in the field of view. Time-resolved exhaust hydrocarbon concentration measurements were found to be lower at the throttled condition.
An experimental investigation of two different methods for swirl induction in a multivalve engine
Authors: Pipitone E , Mancuso U
Published: April 2005

This paper describes an experimental investigation aimed at comparing the swirl effect induced by unbalancing the mass flow through the two intake ports of a multivalve engine head using two different methods: the first one reduced the curtain area of one of the intake valves [different lifts (DL) method]; the second one adopted a sluice-gate-shaped valve, installed upstream of the intake valves [swirl control valve (SCV) method] in order to cause a pressure drop. A steady-flow test rig (equipped with instrumentation for the discharge coefficient and swirl intensity measurement) was realized in order to compare and evaluate the results of both methods and determine their respective validity and limitations; the procedures used for both experimental methods are discussed in detail. The flow characteristics were analysed through changes of lift difference or SCV position; it was found that both DL and SCV methods are effective in swirl induction but the DL mechanism, acting on the valve curtain area, is more effective in flow unbalancing between intake ports, since the flowrate depends linearly on the curtain area. The SCV method, instead, controls the port flowrate, inducing a localized pressure drop, whose intensity depends on the flow velocity in a non-linear manner. For this reason the SCV method can achieve strong swirl intensity only with high obstruction levels, in a narrow regulation window close to full-obstruction conditions.
Direct heat loss to combustion chamber walls in a direct-injection diesel engine: Evaluation of direct heat loss to piston and cylinder head
Authors: Suzuki Y , Shimano K , Enomoto Y , Emi M , Yamada Y
Published: April 2005

The purpose of this study is to clarify the state of the heat loss in a direct-injection diesel engine. Originally developed thin-film thermocouples (TFTs) are embedded into the combustion chamber walls for accurate measurement of instantaneous surface temperature from which instantaneous heat flux is evaluated through the heat conduction equation. Measured points are arrayed on the cavity bottom, the cavity side wall, the piston top, and the cylinder head. The TFTs are designed and fabricated so that disturbance of the temperature field is minimized when they are embedded into the combustion chamber walls. As a result, it is observed that the behaviour of instantaneous temperature and heat flux depends on the radius of the measured point. Measured points located radially inwards seem to be influenced by the combustion flame considerably more than those located outwards because the flame is presumed to stay in and around the cavity which occupies a region around the central axis of the piston. On the other hand, the heat loss ratio, namely the ratio of lost heat to the heat supplied by the fuel, is larger than in a gasoline engine.
1170 consecutive hysterectomies: indications and pathology
Authors: MacKenzie Ian Z. , Naish Caroline , Rees Margaret , Manek Sanjiv
Published: April 2005

Objective: An analysis of consecutive hysterectomies during 1997-99 exploring the relationship between histological findings, operation performed and clinical indication was conducted to observe any trends.

Methods: A retrospective review of histology reports for hysterectomies performed in a large district teaching hospital.

Results: The rate of hysterectomy for women aged over 25 years was 23 per 10,000 women. Menstrual disturbance including endometriosis was the indication in 45%, pelvic tumours including fibroids in 21%, prolapse in 17% and malignant or pre-malignant conditions in 15%; 1% were performed in relation to childbirth. 79% were total abdominal hysterectomies, 4% subtotal and 17% vaginal. 50% included removal of both ovaries and in 8% omentectomy was also performed. The uterus was histologically normal in 20% of abdominal hysterectomies, the rate rising to 70% for vaginal hysterectomies.

Conclusions: The rate of hysterectomy has not changed over the past 15 years, despite the introduction of alternative medical and surgical therapies for managing menstrual problems and fibroids. There may have been a greater proportion performed for malignant and premalignant conditions and genital tract prolapse. There were fewer specimens with no evidence of pathology than is often suggested.
Malignancy arising in residual endometriosis following hysterectomy and hormone replacement therapy
Authors: Soliman Nadia F. , Evans A. Jeremy
Published: April 2005

Two women with adenocarcinoma of the endometrium and a past history of disseminated pelvic endometriosis presented with vaginal bleeding. One also had obstructive uropathy. The two patients had undergone total abdominal hysterectomy with removal of one or both ovaries three and 13 years previously and subsequently were treated with unopposed oestrogen replacement therapy. Adenocarcinoma of the endometrium following endometriosis is a rare condition and few cases are reported in the literature. A summary of the cases and related literature are presented.
Long-term safety and tolerability of continuous-combined hormone therapy in postmenopausal women: results from a seven-year randomised comparison of low and standard doses
Authors: Heikkinen Jorma , Vaheri Raija , Timonen Ulla
Published: April 2005

Objective. To establish the long-term safety profile of four oestradiol valerate/medroxyprogesterone acetate (E2V/MPA) regimens.

Study design. 419 postmenopausal women in parallel treatment groups started treatment with 1 or 2 mg E2V with either 2.5 or 5 mg MPA for 84 cycles of 28 days in a randomised, comparative study. The first 24 month double-blind efficacy period has been previously reported. This report focuses on the open safety period after the first two years until completion of 84 treatment cycles.

Results. A total of 275 women (65.6%) completed the seven-year study. All regimens provided good bleeding control and endometrial protection, with no cases of endometrial hyperplasia or cancer diagnosed. All regimens were well tolerated with a low frequency of adverse effects, mostly occurring within the first two years. The most common drug-related adverse events included breakthrough bleeding, headache/migraine, abdominal pain and mood changes. Very few women (n = 4) receiving the lowest dose option (1 mg E2V + 2.5 mg MPA) reported adverse effects (p<0.009 vs other groups). No serious cardiovascular events occurred in any of the groups, the incidence of strokes was lower than the national incidence for the age group and the incidence of breast cancer was comparable with the national incidence (95% CI). In the lowest dose group, no women had to stop therapy prematurely due to serious adverse events.

Conclusions. The results support the use of lower doses for longterm hormone therapies.
Diabetes and the menopause
Authors: Khoo Cheen Leen , Perera Mahesh
Published: April 2005

As life expectancy increases, women are spending more time in the postmenopausal phase of life. Diabetes is one of the most common chronic diseases in the world and its prevalence is increasing. Type 2 diabetes mellitus is more common than type 1 (it accounts for 90% of all cases) and is most frequent in obese individuals over the age of 40 years. In this review, the main problems faced by postmenopausal diabetic women are examined, and hormone replacement therapy (HRT) in this group of women is discussed. HRT appears to decrease the incidence of type 2 diabetes mellitus and to improve glycaemic control; the results vary according to the type of HRT and the route of administration. HRT also improves lipid profiles and transdermal delivery seems to decrease triglyceride levels in particular. There are conflicting data on the effect of HRT on coronary heart disease (CHD); however, it may be beneficial in younger postmenopausal diabetic women. Cardioprotective treatment adjuncts (such as statins or low-dose aspirin) may be advised in diabetic women with CHD risk factors who require HRT. However, their prescription is currently not recommended solely for the possible prevention of cardiovascular disease. HRT may also protect women from osteoporosis in diabetes, especially in type 1 diabetes mellitus. It is recommended that the lowest possible effective dose is used. In postmenopausal diabetic women in whom HRT is not suitable, alternatives such as bisphosphonates may be employed. In these women, vasomotor symptoms can also be improved using drugs such as venlafaxine or gabapentin. Based on current data, we have proposed a regimen that could be used for women with diabetes.
The use of bisphosphonates in breast cancer
Authors: Lester James , Coleman Robert
Published: April 2005

Bisphosphonates will become increasingly important in the management of patients with breast cancer. Currently, bisphosphonates are used to treat bone metastasis because they effectively relieve pain, prevent pathological fractures and treat hypercalcaemia of malignancy. Recent advances in systemic adjuvant therapies for breast cancer are improving survival but many treatments are detrimental to bone and can increase the risk of fracture. The monitoring of breast cancer patients at risk of developing osteoporosis will become increasingly important as survival times improve and more potent treatments are developed. Bisphosphonates may also play a role as an adjuvant therapy for the prevention of bone metastasis in high-risk breast cancer patients.
Advances in the treatment of endometrial cancer
Authors: Oehler Martin K. , Fung Alison , Jobling Thomas W.
Published: April 2005

Endometrial cancer (EC) most commonly affects postmenopausal women. It is curable if treated early, but tumours with adverse histopathological features or at an advanced stage are associated with a high mortality rate. These cancers require a complex therapeutic approach, consisting of surgery, radiotherapy, chemotherapy and/or hormonal therapy. As one of the leading causes of death from malignancy in women, EC has been subject to intense clinical investigation. This article examines recent advances in the surgical treatment of the disease, such as sentinel lymph node sampling and total laparo scopic hysterectomy, as well as topics such as conservative treatment of EC for fertility preservation. Furthermore, new agents for EC treatment are presented, for example inhibitors of the mTOR pathway and the angiogenesisinhibitor VEGF-trap.
A new selective substrate for cathepsin E based on the cleavage site sequence of α2-macroglobulin
Authors: Yasuda Yoshiyuki , Kohmura Keiko , Kadowaki Tomoko , Tsukuba Takayuki , Yamamoto Kenji
Published: April 2005

Cathepsin E is an intracellular aspartic proteinase of the pepsin family predominantly expressed in cells of the immune system and believed to contribute to homeostasis by participating in host defense mechanisms. Studies on its enzymatic properties, however, have been limited by a lack of sensitive and selective substrates. For a better understanding of the importance of this enzymein vivo, we designed and synthesized a highly sensitive peptide substrate for cathepsin E based on the sequence of the specific cleavage site of α2-macroglobulin. The substrate constructed, MOCAc-Gly-Ser-Pro-Ala-Phe-Leu-Ala-Lys(Dnp)-D-Arg-NH2[where MOCAc is (7-methoxycoumarin-4-yl)acetyl and Dnp is dinitrophenyl], derived from the cleavage site sequence of human α2-macroglobulin, was the most sensitive and selective for cathepsin E, withkcat/Kmvalues of 8–11 μM-1S-1, whereas it was resistant to hydrolysis by the analogous aspartic proteinases cathepsin D and pepsin, as well as the lysosomal cysteine proteinases cathepsins B, L, and H. The assay allows the detection of a few fmol of cathepsin E, even in the presence of plasma and cell lysate, and gives accurate results over a wide enzyme concentration range. This substrate might represent a useful tool for monitoring and accurately quantifying cathepsin E, even in crude enzyme preparations.
Evaluation of a high-sensitivity turbidimetric immunoassay for serum C-reactive protein: application to the study of longitudinal changes throughout normal pregnancy
Authors: Bertran Núria , Camps Jordi , Fernández-Ballart Joan , Murphy Michelle M. , Arija Victoria , Ferré Natàlia , Tous Mònica , Joven Jorge
Published: April 2005

C-Reactive protein has been associated with several complications of pregnancy. The aims of the present study were: (1) to evaluate a turbidimetric immunoassay for the measurement of C-reactive protein; and (2) to investigate the chronological changes of the levels of this protein from preconception throughout normal pregnancy and its relationship with variables associated with preconception and pregnancy outcome. Inter-assay imprecision was <5% for C-reactive protein >1mg/L and 18% at a mean value of 0.33mg/L. The limit of detection was 0.10mg/L. The method was linear between 0.10 and 30mg/L. There were no observed interferences from jaundice, hemolysis, lipemia or paraproteinemia at the levels studied. There was good agreement with the nephelometric method. A total of 39 women were studied at preconception, at 8, 20 and 32weeks of pregnancy, and in labor. Preconception C-reactive protein concentration was 1.17±0.18mg/L and increased (p<0.001) throughout pregnancy up to 5.69±0.82mg/L. Body mass index at preconception and weight gain during pregnancy were the main factors associated with this increase in C-reactive protein.
Florística e fitossociologia de uma floresta de vertente na Amazônia Central, Amazonas, Brasil
Authors: Oliveira Arlem Nascimento de , Amaral Iêda Leão do
Published: April 2005

O estudo florístico e fitossociológico de árvores, palmeiras e lianas com diâmetro à altura do peito (DAP) >10 cm, em uma floresta de vertente na Amazônia Central (2º35'45" S e 60º12'40" W), foi realizado empregando-se 20 parcelas de 50 x 10 m, distribuídas em dois transectos paralelos de 500 x 10 m. Foram registrados 771 indivíduos, pertencentes a 50 famílias, 120 gêneros e 239 espécies. Das espécies amostradas, 44% são "localmente raras". Sapotaceae, Lecythidaceae, Fabaceae, Caesalpiniaceae e Chrysobalanaceae constituíram as cinco famílias com maior riqueza de espécies e número de indivíduos. Dos 771 indivíduos amostrados, mais de 65% apresentaram DAP > 20 cm. As espécies Eschweilera bracteosa e Protium apiculatum apresentaram os maiores valores de IVI. Cerca de 83% das espécies encontram-se distribuídas aleatoriamente no hectare amostrado. O índice de diversidade Shannon-Wiener foi de 5,01 nats.indivíduo-1, com uniformidade de 0,91, valores altos no contexto de levantamentos semelhantes na região. A heterogeneidade edáfica e topográfica da área, as taxas de recrutamento de novos indivíduos e de espécies "localmente raras" à comunidade local, podem ter contribuído para as altas dissimilaridade (36,2%) e diversidade florísticas documentadas neste estudo.
Diversidade de Agaricales (Basidiomycota) na Reserva Biológica Walter Egler, Amazonas, Brasil
Authors: Souza Helenires Queiroz de , Aguiar Izonete de Jesus Araújo
Published: April 2005

Foi realizado um estudo dos representantes da Ordem Agaricales Clements (Hymenomycetes, Basidiomycotina), ocorrentes na Reserva Biológica Walter Egler, situada na Estrada AM-010, Manaus-Itacoatiara, Km 64, Latitude 02° 43' S e Longitude 59° 47' W, Rio Preto da Eva, Amazonas. A área abrange 709 ha de floresta de terra firme primária. As coletas foram realizadas no período de dezembro de 2000 a junho de 2001 e seguiu-se a metodologia usual para identificação de Agaricales. Foram estudadas um total de 39 espécies, distribuídas em 13 gêneros e seis famílias: Polyporaceae: Pleurotus sp.; Hygrophoraceae: Hygrocybe cf. megistospora, Hygrocybe aff. miniceps, Hygrocybe occidentalis var. scarletina, e mais oito espécies de Hygrocybe indeterminadas; Tricholomataceae: Clitocybe sp., Hydropus sp.1 e Hydropus sp.2, Macrocystidia sp., Marasmiellus sp., Marasmius bellus, Marasmius haedinus var. haedinus,Marasmius cf. leoninus, Marasmius cf. mazatecus, Marasmius cf. ruber,Marasmius cf. setulosifolius, Marasmius tageticolor, Marasmius cf. variabiliceps var. variabiliceps, Marasmius sp.1, Marasmius sp.2, Marasmius sp.3 e Marasmius sp.4, Tricholoma sp.; Agaricaceae: Agaricus sp.1 e Agaricus sp.2, Lepiota sp., Cystoderma sp.; Entolomataceae: Entoloma cf. azureoviride, Entoloma cf. cystidiophorum, Entoloma strigosissima, Entoloma sp.; Russulaceae: Lactarius panuoides. Destas, Entoloma azureoviride, Hygrocybe miniceps, Lactarius panuoides, Marasmius cf. mazatecus, Marasmius cf. setulosifolius e Marasmius variabiliceps var. variabiliceps, provavelmente, estão sendo aqui citadas pela primeira vez, para o Brasil. Com exceção de Marasmius tageticolor, as demais espécies são citadas pela primeira vez, para a Reserva Egler. São fornecidas tabelas com a ocorrência das espécies de acordo com o gradiente topográfico (baixio, vertente, platô) e seus respectivos habitats.
Esterases no exame da estrutura populacional de Camu-camu (Myrciaria dubia (Kunth) McVaugh-Myrtaceae)
Authors: Teixeira Aylton Saturnino , Chaves Lena da Silva , Yuyama Kaoru
Published: April 2005

Dois sistemas enzimáticos (esterase e esterase-D), analisados pela técnica de eletroforese em gel de amido, em folhas jovens de plantas cultivadas em terra firme, de sementes provenientes de três amostras de populações naturais de camu-camu, Myrciaria dubia (Kunth) McVaugh-Myrtaceae, procedentes de Iquitos, Boa Vista e Uatumã, revelaram a presença de 6 locos: Est-1, Est-2, Est-3, Est-4, Est-D1 e Est-D2. Dois dos seis locos gênicos examinados no presente estudo (Est-3 e Est-D2) mostraram-se polimórficos, sendo desse modo considerados valiosos no estudo de caracterização da estrutura populacional da espécie. Os padrões de polimorfismo revelados nos locos Est-3 e Est-D2 de camu-camu, são típicos de enzimas monoméricas e diméricas, respectivamente. O loco Est-3 apresentou um grande desbalanço genético dentro e entre as amostras populacionais examinadas, devido ao excessivo número observado de plantas heterozigóticas em relação ao número esperado. O loco Est-D2 apresentou um polimorfismo exclusivo para os alelos Est-D2¹,Est-D2² e Est-D2³, e um bom balanço genético na amostra populacional de Uatumã. Em função disso, dentre os demais locos gênicos aqui investigados, o loco Est-D2 parece ser o mais adequado para identificação e delimitação de prováveis estoques de camu-camu. Portanto, recomenda-se que esse loco esteja presente na lista dos marcadores isoenzimáticos a serem usados em futuras prospecções sobre genética populacional dessa espécie na região amazônica. Dados sobre a distribuição das freqüências alélicas, estimativas das distâncias genéticas, e estimativas de variação genética nos 6 locos de esterases examinados, foram eficazes na demonstração de diferenças genéticas entre as amostras populacionais examinadas da espécie. Os maiores valores de heterozigozidade média (0,1353); proporção de locos polimórficos (0,33) e número médio de alelos por loco (1,33) revelados na amostra populacional de Uatumã, devem-se ao fato dessa amostra ter apresentado um loco polimórfico a mais (Est-D2), em relação as demais amostras investigadas.
Primeiro registro de Eufriesea laniventris (Ducke, 1902) (Hymenoptera, Apidae, Euglossini) no Amazonas, Brasil
Authors: Storti Eliana Fernandez , Storti Filho Atilio , Oliveira Márcio Luiz de
Published: April 2005

É registrada pela primeira vez a ocorrência de Eufriesea laniventris no Amazonas. No ano 2000, foram coletados seis exemplares na região de Manaus (2º 36' S e 60º 02' W) atraídos pelas substâncias odoríferas 1,8 cineol e salicilato de metila.
Estudo de parâmetros físicos, químicos e hídricos de um Latossolo Amarelo, na região Amazônica
Authors: Marques Jean Dalmo de Oliveira , Libardi Paulo Leonel , Teixeira Wenceslau Geraldes , Reis Ana Maria
Published: April 2005

Estudou-se os atributos físicos, hídricos e químicos de um Latossolo sob sistema de agroflorestal na região Amazônica. O solo foi descrito morfologicamente e amostras com estrutura deformada foram coletadas para caracterização física e química. A análise das propriedades hidráulicas foi realizada a partir de amostras indeformadas coletadas a cada camada de 0,10 m até 1,00 m de profundidade com 5 repetições para determinação da condutividade hidráulica do solo saturado (Ko) pelo método do permeâmetro de carga decrescente e determinação das curvas de retenção (fim(teta)), utilizando as tensões de 1, 2 e 4 kPa (funis de placa porosa) e 10, 30, 50, 100, 500 e 1500 kPa (câmaras de pressão com placa porosa). As demais análises foram realizadas até 1,50 m de profundidade. Os valores de Ko nas camadas apresentaram grande homogeneidade estando compreendido entre 2,22 a 3,20 cm dia-1, sendo relacionados com variação da densidade do solo e porosidade. A retenção hídrica demonstra que o solo tem a capacidade de reter elevada quantidade de água, mesmo quando submetido a elevados potenciais, indicando uma baixa disponibilidade para as plantas. As curvas de retenção não apresentaram um bom ajuste pela equação de van Genuchten , sugerindo uma distribuição de poros bimodal.
Growth rate of a terra firme rain forest in Brazilian Amazonia over an eight-year period in response to logging
Authors: Carvalho João Olegário Pereira de , Silva José Natalino Macedo , Lopes José do Carmo Alves
Published: April 2005

This paper deals with growth rates of trees > 5cm dbh over an eight-year period from 257 species at the Tapajós National Forest. The discussion is centred on the behaviour of the forest after logging. Permanent sample plots were established in 1981 and measured at the first time. The area was logged in 1982. Measurements after logging occurred in 1983, 1987 and 1989. Considering all species together, diameter increment was similar for both intensities of logging until five years after logging. Light-demanding species showed significantly higher growth rates than shade-tolerant species in the logged forest, with greater increment in the heavier treatment intensity. Commercial species also had higher growth rates in the heavier logged area, although those were significantly different only in the period from one to five years after logging. In the undisturbed forest, growth rates increased with increasing dbh size. At species level, growth rate varied between and within treatments, as well as between trees within species, depending mainly on degree of canopy opening. The logging favoured the growth of commercial species, chiefly the light-demanders. Therefore, if the same growth conditions continue being given, for example by silvicultural treatments, to those species of commercial interest, the forest would reach a stock available for harvesting around year 30 after logging. However, the high variation in increment rates indicates that an eight-year period is not sufficient to allow predictions on cutting cycles or polycyclic management systems for the study forest.
Contribuição ao conhecimento morfológico das espécies de leguminosae comercializadas no estado do Pará, como "angelim"
Authors: Ferreira Gracialda Costa , Hopkins Michael John Gilbert , Secco Ricardo de S.
Published: April 2005

Sete espécies de Leguminosae comercializadas como "angelim", no estado do Pará, foram analisadas quanto aos aspectos morfológicos dos órgãos vegetativos e reprodutivos. Este estudo visou determinar diferenças básicas entre as espécies comercializadas com esta denominação vernacular, a fim de auxiliar no processo de identificação taxonômica das mesmas. Foi elaborada uma chave dicotômica para separar as espécies estudadas (Andira surinamensis, Dinizia excelsa, Hymenolobium excelsum, H. modestum, H. pulcherrimum, H. petraeum e Vatairea paraensis). As principais características utilizadas no campo, para separação das espécies estudadas, foram folha, folíolo, casca e tronco, porém, espécies de Andira, Hymenolobium e Vatairea, por apresentarem-se desprovidas de folhas no período fértil, necessitam de dados dos órgãos reprodutivos.
Ocupação cabocla e extrativismo madeireiro no alto capim: uma estratégia de reprodução camponesa
Authors: Medina Gabriel
Published: April 2005

Com o avanço da atividade madeireira através da Bacia Amazônica, comunidades localizadas ao longo das fronteiras madeireiras passam a ter oportunidade de vender os direitos de extração da madeira de suas áreas. O valor localmente percebido e as decisões das populações locais sobre a forma de uso de seus recursos contrastam fortemente com as visões globalmente construídas sobre o valor da floresta tropical. Este valor local é baseado em representações que consideram a importância local dos produtos florestais e no contexto em que estas representações são construídas. Para explorar esta temática, o artigo começa com uma reconstrução do histórico de uma comunidade cabocla enfocando nas dinâmicas de uso da floresta. Para os comunitários, a madeira sempre representou uma herança que poderia ser gasta ao longo do tempo. A madeira foi o principal produto da floresta com valor de mercado e, até recentemente, sua extração não reduziu significativamente o acesso aos outros produtos florestais. A madeira, então, foi vista como uma herança com valor de troca e uso não conflituoso. Quatro fatores sócio-econômicos influenciaram a continuidade das vendas de madeira mesmo quando as perdas no consumo de produtos não madeireiros ficaram evidentes: 1) relações paternalistas entre os compradores da madeira e os caboclos; 2) dificuldades de gestão comum dos recursos; 3) especialização na extração de madeira e dependência de produtos externos e; 4) crescente envolvimento no mercado que demandou maior quantidade de dinheiro para suprir novas necessidades.
Valor nutricional do mel e pólen de abelhas sem ferrão da região Amazônica
Authors: Souza Rosa Cristina da Silva , Yuyama Lucia Kiyoko Ozaki , Aguiar Jaime Paiva Lopes , Oliveira Francisco Plácido Magalhães
Published: April 2005

Avaliou-se os constituintes nutricionais de amostras do mel e pólen das espécies Melipona seminigra merrillae (jandaíra), Melipona compressipes manaosensis (jupará), Melipona rufiventris paraensis (uruçu boca de ralo), provenientes do meliponário da Fazenda Poranga no município de Itacoatiara - AM e Meliponário Abelhudo em Manaus - AM. Os resultados demonstraram o potencial do mel como fonte de energia, particularmente a M. rufiventris com 305,3±2,4 kcal em 100g. O pólen da espécie M. compressipes apresentou a maior concentração de proteína 15,7±0,0% e energia 309,8±0,8 kcal. Tais constatações sugerem a implementação de novos estudos visando à incorporação destes produtos na dieta dos amazônidas, possibilitando uma nova fonte alternativa de alimento potencialmente nutritivo e saudável.
Aspectos florísticos de 13 hectares da área de Cachoeira Porteira-PA
Authors: Lima Filho Diógenes de Andrade , Revilla Juan , Amaral Iêda L. do , Matos Francisca Dionizia de A. , Coêlho Luiz de Souza , Ramos José Ferreira , Silva Gláucio Belém da , Guedes José de Oliveira
Published: April 2005

Este trabalho descreve a composição florística na área do reservatório da futura Hidrelétrica de Cachoeira Porteira - PA (localizada na margem esquerda do rio Trombetas), e a caracterização da vegetação. São apresentados dados sobre a abundância, dominância, freqüência e os Índices de Valor de Importância das espécies (IVIE) e o Índice de Valor de Importância das Famílias (IVIF) e a análise da estrutura horizontal da floresta. Os estudos desenvolvidos neste trabalho mostram as espécies e famílias mais importantes da área com relação a sua influência, na definição do perfil estrutural da floresta, além da identificação dos diferentes tipos de vegetação. Os 13 hectares de floresta inventariados sustentam 4.583 indivíduos, abrangendo árvores, palmeiras e cipós com DAP > 10cm, distribuídos em 359 espécies, 217 gêneros e 55 famílias (três medidas de importância ecológica; abundância, dominância e freqüência, expressas como três porcentagens, foram somadas para obter um Índice de Valor de Importância (IVIE) das espécies). As duas espécies com os maiores IVIE, em toda a área estudada pesquisada, foram Eschweilera coriacea (DC) S. A . Mori, com 15,24% e Micropholis guyanensis (A . DC.) Pierre com 10,87%. As famílias que apresentaram os maiores Índices de Valor de Importância (IVIF) nos 13 hectares, foram Caesalpiniaceae (31,45%) e Sapotaceae (30,34%).
Durabilidade natural do estipe de pupunha (Bactris gasipaes Kunth, Arecaceae) II: insetos
Authors: Abreu Raimunda Liege Souza de , Jesus Maria Aparecida de
Published: April 2005

Neste trabalho estão apresentados os resultados da durabilidade natural do estipe (madeira) de Bactris gasipaes Kunth (pupunha), quando submetido ao ataque de insetos xilófagos, em ensaios em ambiente florestal e urbano. Foram utilizados dez palmeiras, cinco com espinhos e cinco sem espinhos, de plantios da Fazenda Experimental da Universidade Federal do Amazonas, localizada no km 40 da rodovia Manaus-Boa Vista (BR 174). De cada uma das palmeiras foram cortados três discos de aproximadamente 30 cm de espessura, retirados da base, do meio e do topo. No ambiente florestal, os discos foram distribuídos aleatoriamente, em área próxima ao plantio, no espaçamento de 0,5m, permanecendo durante 18 meses, período no qual foram efetuadas seis inspeções trimestrais para avaliar o grau de deterioração e coleta de insetos. Para o ensaio em condição urbana, os discos foram secionados axialmente para a retirada da medula e distribuídos aleatoriamente, nas posições côncava e convexa, sobre uma estrutura de madeira, localizada no Campus do INPA em Manaus, e inspecionados bimestralmente por um ano. Os resultados do ensaio no ambiente florestal indicaram que a maioria dos discos foi deteriorada por térmitas e a vida útil da base foi em torno de 18 meses, a do meio e do topo em torno de 15. As principais espécies de cupins foram: Heterotermes tenuis (Hagen) (Rhinotermitidae) responsável pela deterioração da parte basal, mediana e o topo; Nasutitermes similis Emerson (Termitidae) que infestou a região da base e do meio; Anoplotermes sp.(Termitidae) e Nasutitermes tatarandae (Holmgren) (Termitidae) responsáveis pela infestação da parte mediana do estipe. No ambiente urbano, o principal responsável pela deterioração das amostras foi o besouro Dinoderus bifoveolatus Wollston (Bostrichidae), e em seguida, o térmita N. similis.
Mapeamento do uso e cobertura da terra a partir da segmentação e classificação de imagens-fração solo, sombra e vegetação derivadas do modelo linear de mistura aplicado a dados do sensor TM/Landsat5, na região do reservatório de Tucuruí - PA
Authors: Vasconcelos Cíntia Honório , Novo Evlyn Márcia Leão de Moraes
Published: April 2005

Técnicas de sensoriamento remoto são fundamentais para o monitoramento das mudanças de uso da terra, principalmente em áreas extensas como a Amazônia. O mapeamento de uso da terra, geralmente é realizado por métodos de classificação manual ou digital pixel a pixel, os quais consomem muito tempo. Este estudo aborda a aplicação do modelo linear de mistura em uma imagem Landsat-TM segmentada para o mapeamento das classes de uso da terra na região do reservatório de Tucuruí-PA para os anos de 1996 e 2001.
Ocorrência de Herminodes sp. (Lepidoptera: Noctuidae) em pupunheira nos estados do Acre e Rondônia, Brasil
Authors: Thomazini Marcílio José
Published: April 2005

É relatado a ocorrência de Herminodes sp. em plantas de pupunha na área experimental da Embrapa Acre, Rio Branco, AC e no Projeto Reca, Vila Nova Califórnia, RO, Brasil. São descritas as principais características deste inseto e os danos por ele causados. Este é o primeiro registro de lagartas do gênero Herminodes causando dano em pupunheiras nos estados do Acre e Rondônia.
Calogênese do híbrido Theobroma grandiflorum x T. obovatum (Sterculiaceae)
Authors: Venturieri Giorgini Augusto , Venturieri Giorgio Cristino
Published: April 2005

O declínio da cacauicultura na amazônia tem sido causado pela doença vassoura-de-bruxa (Crinipellis perniciosa). Um híbrido interespecífico do mesmo gênero (Theobroma grandiflorum x T. obovatum) tem demonstrando resistência a esta doença. Avaliou-se a calogênese deste híbrido com a finalidade de sua propagação massiva. Os explantes usados (tegumento, cotilédone e embrião) foram postos para desenvolver em condições estéreis em meio de cultura LPm mais água de coco (50 ml/l), glucose (20 g/l), 2,4 - D (2 mg/l), Thidiazuron - TDZ nas concentrações de 0, 5 e 10 µg/l, carvão ativado (2 g/l) em gelrite (2 g/l) a um pH de 5,8. Cada concentração de TDZ x tipo de tecido foi considerado um tratamento. As culturas foram mantidas no escuro, à temperatura de 22 ± 2 ºC. Os tecidos não mostraram diferenças significativas quanto a proporção do explante recoberto por calos (p= 0,14) embora notou-se que nos cotilédones tenha sido maior. A dosagem de TDZ nitidamente não influenciou no recobrimento de calos (p= 0,94). Quanto a freqüência, os tecidos mostraram diferentes capacidades de desenvolver calos (p= 0,02) sem mostrar-se influenciados pela dosagem de TDZ (p = 0,66). Os explantes de cotilédones foram os que formaram calos em maior freqüência. Houve uma leve tendência de que quanto menor a dosagem de TDZ maior a freqüência de calos obtidos. Não foi constatada interação entre tipo de calo/frasco x dosagem de TDZ (p = 0,32).
Densidade básica da madeira de um ecossistema de "campina" em Roraima, Amazônia brasileira
Authors: Barbosa Reinaldo Imbrozio , Ferreira Carlos Alberto Cid
Published: April 2005

Densidade básica (g.cm-3: peso seco / volume úmido) da madeira foi determinada para 13 das principais espécies arbóreo-arbustivas de um ecossistema de "campina" (caatinga amazônica) situado em Roraima, extremo norte da Amazônia brasileira. As amostras de madeira para o cálculo da densidade básica de cada espécie foram compostas por "discos amostrais" (casca, alburno e cerne) de diferentes classes diamétricas. No total, foram amostrados 98 indivíduos, perfazendo 150 peças de madeira (52 com diâmetro < 1,6cm; 63 entre 1,6-3,2cm, 27 entre 3,2-4,8cm e 8 > 4,8cm). A espécie de maior densidade média foi Matayba arborescens (Aubl.) Radlk. (0,68 g.cm-3), seguida de Humiria balsamifera (Aubl.) St. Hill. (0,67 g.cm-3) e Pera schomburgkiana Müel. Arg. (0,64 g.cm-3). As classes de menor diâmetro foram também as de menor valor absoluto: 0,59 ± 0,06 (DP) g.cm-3 (< 1,6cm), 0,64 ± 0,08 g.cm-3 (1,6-3,2cm), 0,67 ± 0,06 g.cm-3 (3,2-4,8cm) e 0,69 ± 0,10 g.cm-3 (> 4,8cm). A média ponderada pela biomassa do ecossistema foi de 0,64 ± 0,08 g.cm-3. Este resultado é 15,2% inferior ao comumente utilizado para transformação de volume de madeira em biomassa para ecossistemas de "campina" na Amazônia, influenciando diretamente nos cálculos de emissão de gases do efeito estufa.