carlos martinez - Academia.edu (original) (raw)

Papers by carlos martinez

Jornadas de Bibliotecas Digitales, 2000

International Conference on Sensor Technologies and Applications, SensorComm, 2007

Sometimes wireless sensors could be placed randomly without predetermined coordinates, so systems... more Sometimes wireless sensors could be placed randomly without predetermined coordinates, so systems to self-locate in an area should be studied. This paper shows two approaches developed by us where wireless sensors could find their position using WLAN technology. The scenario is an indoor environment that contains walls, interferences, multipath effect, humidity and temperature variations, etc., and both approaches are based

International Journal of Electrical Power & Energy Systems, 2008

This work will not put forward yet another scheme for short-term load forecasting but rather will... more This work will not put forward yet another scheme for short-term load forecasting but rather will provide evidences that may improve our understanding about fundamental issues which underly load forecasting problems. In particular, load forecasting will be decomposed into two main problems, namely dynamical prediction and pattern mapping. It is argued that whereas the latter is essentially static and becomes nonlinear when weekly features in the data are taken into account, the former might not be deterministic at all. In such cases there is no determinism (serial correlations) in the data apart from the average cycle and the best a model can do is to perform pattern mapping. Moreover, when there is determinism in addition to the average cycle, the underlying dynamics are sometimes linear, in which case there is no need to resort to nonlinear models to perform dynamical prediction. Such conclusions were confirmed using real load data and surrogate data analysis. In a sense, the paper details and organizes some general beliefs found in the literature on load forecasting. This sheds some light on real model-building and forecasting problems and helps understand some apparently conflicting results reported in the literature.

IJCSNS, 2009

We present the results for the study and classification of urine sediments and coproparasitoscopi... more We present the results for the study and classification of urine sediments and coproparasitoscopic specimens using neural networks. This method has the additional advantage of taking into account the internal geometry of certain structures and to classify them according to certain parameters such as fractal dimension and entropies. In this case we use Renyi and Tsallis entropies with order q. These results are introduced as information for a hierarchical neuronal network, and allows increasing the precision of the urine sediment and parasite microscopic determination..

Plant Science, 2001

In photosynthetic tissues superoxide dismutase (SOD) plays an important role by scavenging the su... more In photosynthetic tissues superoxide dismutase (SOD) plays an important role by scavenging the superoxide radical whose production is an usual reaction in chloroplast thylakoids. To test the differential response of SOD, two Andean potato species differing in frost resistance, Solanum curtilobum (frost resistant) and Solanum tuberosum (frost sensitive), were subjected to methyl viologen-mediated oxidative stress and polyethylene glycol (PEG)-induced water stress. A significant increment (approximately two-fold) in total SOD and FeSOD activity, which occupied about 50% of the total activity, was found when leaves of S. curtilobum were exposed to water stress. In contrast, the SOD activity in leaves of S. tuberosum remained unchanged. The exposure of leaves of S. curtilobum to oxidative stress increased total SOD and FeSOD activity by 350%. High correlation between SOD activity and the F v /F m ratio under both PEG induced water stress and MV-mediated oxidative stress was observed. This suggests that SOD can protect PSII from superoxide generated by oxidative and water stress. The higher SOD activity could be an important mechanism to explain why some natives Andean potato like S. curtilobum are more resistant to abiotic stresses than S. tuberosum.

International braz j urol, 2004

Objectives: To analyze the behavior of the prostate specific antigen velocity (PSAV) in localized... more Objectives: To analyze the behavior of the prostate specific antigen velocity (PSAV) in localized prostate adenocarcinoma.

Menopause, 2007

To verify whether tibolone is preferentially prescribed to women at an increased risk for endomet... more To verify whether tibolone is preferentially prescribed to women at an increased risk for endometrial and breast cancer compared with women who were prescribed combined estrogen + progestogen therapies, including sequential conjugated equine estrogens/norgestrel, sequential conjugated equine estrogens/medroxyprogesterone acetate, continuous conjugated equine estrogens/medroxyprogesterone acetate, or continuous 17beta-estradiol/norethisterone acetate. This was a descriptive study using the General Practice Research Database, a UK primary care database. A total of 16,746 women who, between July 1, 1999, and June 30, 2001, were prescribed either tibolone or one of the estrogen + progestogen regimens listed above were included. The main outcome measures were risk factors associated with endometrial cancer and breast cancer. The clinical background of women who were prescribed tibolone differed from that of women who were prescribed combination products. More frequently than expected, women who were most recently prescribed tibolone had a history of chronic breast disease, a personal history of breast cancer, or a history of (long-term) estrogen-only therapy. Furthermore, medical records of this group of women showed more frequent reports of hypertension and previous uterine procedures. This study confirms previous findings that in the United Kingdom, general practitioners seem to prescribe tibolone preferentially to women with increased risks of breast and endometrial cancer as compared with women who are prescribed estrogen + progestogen products.

Tetrahedron, 2004

The development of an efficient route for the preparation of (2S)-2-[3-{[(5-methylisoxazol-3-yl)c... more The development of an efficient route for the preparation of (2S)-2-[3-{[(5-methylisoxazol-3-yl)carbonyl]amino}-2-oxopyridin-1(2H)-yl]pent-4-ynoic acid (4), a key intermediate in the synthesis of a human rhinovirus (HRV) protease inhibitor, is presented. In the presence of 40% acetonitrile, the alkaline protease from Bacillus lentus can catalyze the kinetic resolution of racemic ester 7 to afford (S)-acid 4 in 49% chemical yield/per cycle with 98%

Organic Process Research & Development, 2008

This article is part of the Fluorine Chemistry special issue. ... The multikilogram production of... more This article is part of the Fluorine Chemistry special issue. ... The multikilogram production of the proline derivative 1, a key intermediate of a HIV protease inhibitor, required the design of a synthetic route able to be safely, effectively, and easily scaled up. Synthesis of the ...

Environmental and Experimental Botany, 2011

To investigate the ability of pioneer and late-successional species to adapt to a strong light en... more To investigate the ability of pioneer and late-successional species to adapt to a strong light environment in a reforestation area, we examined the activities of antioxidant enzymes in relation to photosystem II, chlorophyll a fluorescence and photosynthetic pigment concentration for eight tropical tree species grown under 100% (sun) and 10% (shade) sunlight irradiation. The pioneer (early-succession) species (PS) were Cecropia

Biology of Blood and Marrow Transplantation, 2011

Stomatal sensitivity to ABA related to pH and NO-3, PO4-3 and Ca+2 levels of xylem sap: Stomatal ... more Stomatal sensitivity to ABA related to pH and NO-3, PO4-3 and Ca+2 levels of xylem sap: Stomatal sensitivity to abscisic acid (ABA) can be modified by variations in the xylem sap traits such as pH, Ca2+, NO3- and PO43- concentrations. In order to verify this hypothesis, plants of Licopersicon esculentum L. cv. Santa Clara were submitted to sudden and slow

PLANT PHYSIOLOGY, 2001

The binding protein (BiP) is an important component of endoplasmic reticulum stress response of c... more The binding protein (BiP) is an important component of endoplasmic reticulum stress response of cells. Despite extensive studies in cultured cells, a protective function of BiP against stress has not yet been demonstrated in whole multicellular organisms. Here, we have obtained transgenic tobacco (Nicotiana tabacum L. cv Havana) plants constitutively expressing elevated levels of BiP or its antisense cDNA to analyze the protective role of this endoplasmic reticulum lumenal stress protein at the whole plant level. Elevated levels of BiP in transgenic sense lines conferred tolerance to the glycosylation inhibitor tunicamycin during germination and tolerance to water deficit during plant growth. Under progressive drought, the leaf BiP levels correlated with the maintenance of the shoot turgidity and water content. The protective effect of BiP overexpression against water stress was disrupted by expression of an antisense BiP cDNA construct. Although overexpression of BiP prevented cellular dehydration, the stomatal conductance and transpiration rate in droughted sense leaves were higher than in control and antisense leaves. The rate of photosynthesis under water deficit might have caused a degree of greater osmotic adjustment in sense leaves because it remained unaffected during water deprivation, which was in marked contrast with the severe drought-induced decrease in the CO 2 assimilation in control and antisense leaves. In antisense plants, the water stress stimulation of the antioxidative defenses was higher than in control plants, whereas in droughted sense leaves an induction of superoxide dismutase activity was not observed. These results suggest that overexpression of BiP in plants may prevent endogenous oxidative stress.

Case Reports in Gastroenterology, 2012

A bezoar is an intraluminal mass formed by the accumulation of undigested material in the gastroi... more A bezoar is an intraluminal mass formed by the accumulation of undigested material in the gastrointestinal tract. Trichobezoar is a rare condition seen almost exclusively in young women with trichotillomania and trichotillophagia. When not recognized, the trichobezoar continues to grow, which increases the risk of severe complications such as gastric ulceration and even perforation. Formation of a gallstone within the trichobezoar (tricholithobezoar) is an event that has not yet been described. We report the case of a 22-year-old woman admitted to the emergency room with signals and symptoms of an epigastric mass and perforative acute abdomen. Radiological study revealed bilateral pneumoperitoneum. Personal history revealed depressive syndrome, trichotillomania and trichophagia. With a diagnosis of visceral perforation, an urgent exploratory laparotomy was performed. This confirmed the diagnosis of gastric perforation due to a large trichobezoar with the formation of a gastrolith that was removed by anterior gastrotomy. Biochemical study of the gastric stone revealed that it was composed of bile salts. There were no complications. The patient was discharged on the 5th postoperative day and was referred for psychiatric treatment.

Ferraro's Fundamentals of Maxillofacial Surgery, 2014

Case Reports in Gastroenterology, 2011

Inflammatory fibroid polyps (Vanek's tumor) are rare benign localized lesions originating in the ... more Inflammatory fibroid polyps (Vanek's tumor) are rare benign localized lesions originating in the submucosa of the gastrointestinal tract. Intussusceptions due to inflammatory fibroid polyps are uncommon; moreover, ileo-ileal intussusception with small bowel necrosis and perforation has rarely been reported. We report a 56-year-old woman who was admitted two days after complaints of nausea and vomiting. Abdominal examination revealed distension, signs of gastrointestinal perforation and clanging intestinal sounds. The patient underwent a emergency laparotomy which found a 17-cm invaginated mid-ileal segment with necrosis, perforation and fecal peritonitis. The ileal segment was resected and single-layer end-to-end anastomosis was performed. Histopathological analysis showed an ulcerative lesion with variable cellularity, formed by spindle cells with small number of mitosis and an abundant inflammatory infiltrate comprising mainly eosinophils. Immunohistochemistry confirmed the diagnosis of ileal Vanek's tumor. Although inflammatory fibroid polyps are seen very rarely in adults, they are among the probable diagnoses that should be considered in obstructive tumors of the small bowel causing intussusception with intestinal necrosis and perforation.

Case Reports in Gastroenterology, 2009

Schwannomas are neoplasms originating from Schwann cells, which are the cells forming nerve sheat... more Schwannomas are neoplasms originating from Schwann cells, which are the cells forming nerve sheaths. These neoplasms generally involve peripheral nerves. They rarely affect the gastrointestinal tract and primary colon involvement is extremely rare. The objective of the present paper was to present a case of primary schwannoma of the sigmoid colon, unassociated with von Recklinghausen disease, that was histopathologically confirmed by means of an immunohistochemical panel. The patient was a 71-year-old woman who had had rectal bleeding when evacuating, with pain and tenesmus, for 4 months. She underwent colonoscopy, which identified a raised submucous lesion of 2.8 cm in diameter, located in the sigmoid colon, 30 cm from the anal margin. During examination, loop polypectomy with lesion excision was performed. Histopathological evaluation showed that this was a tumor of stromal origin. Its resection margins were compromised by neoplasia, and colon resection by means of videolaparoscopy was indicated. Conventional histopathological examination using the hematoxylin-eosin technique suggested that the neoplasm was of mesenchymal origin. An immunohistochemical panel was run for etiological confirmation, using anti-CD34 antibodies, desmin, cytokeratins (AE1/AE3), cKit, chromogranin and S-100 protein. The panel showed intense immunoexpression of S-100 protein. Investigation of the proliferative activity rate using Ki-67 antibodies showed that there was a low rate of mitotic activity, thus confirming the diagnosis of primary benign schwannoma of the colon. The patient's postoperative evolution was uneventful and she remains in good health, without signs of tumor recurrence, 15 months after surgical excision. . Positive immunoexpression of the Ki-67 nuclear proliferation factor in fewer than 5% of the fields studied (immunohistochemistry, 100×).

Scientia Agricola, 2003

Plants present different degrees of adaptation to aluminium (Al) concentrations in the soil, and ... more Plants present different degrees of adaptation to aluminium (Al) concentrations in the soil, and the understanding of this characteristic can lead to a viable option for the utilization of acid soils. The objective of this experiment was to evaluate the effects of five Al concentrations (0, 50, 100, 200, and 400 µmol L -1 ) on the growth of 'Rangpur' lime ( Citrus limonia Osbeck) and 'Volkamer' lemon (Citrus volkameriana Hort. ex Tan.), and tangerine rootstocks 'Cleópatra' (Citrus reshni Hort. ex Tan) and 'Sunki' ( Citrus sunki Hort. ex Tan.), in hydroponic culture. The treatments were arranged in a randomized block design, with four replications. For all rootstocks, the relative growth rate in terms of plant total fresh matter increased under low and, decreased under large Al concentrations. Growth of the shoot, leaf area ratio and leaf weight ratio decreased for all rootstocks in the presence of Al. The 'Rangpur' lime had a decrease of the root system growth, starting from 23 µmol L -1 of Al. For the remaining rootstocks, this growth reached maximum values at 91 to 117 µmol L -1 of Al, respectively. Considering all the evaluated characteristics of plant growth, the ' Rangpur' lime was the most susceptible to Al.

Trees, 1999

Predawn leaf water potential, stomatal conductance and microclimatic variables were measured on 1... more Predawn leaf water potential, stomatal conductance and microclimatic variables were measured on 13 sampling days from November 1995 through August 1996 to determine how environmental and physiological factors affect water use at the canopy scale in a plantation of mature clonal Eucalyptus grandis Hill ex-Maiden hybrids in the State of Espirito Santo, Brazil. The simple "big leaf" Penman-Monteith model was used to estimate canopy transpiration. During the study period the predawn leaf water potential varied from -0.4 to -1.3 MPa, with the minimum values observed in the winter months (June and August 1996), while the average estimated values for canopy conductance and canopy transpiration fell from 17.3 to 5.8 mm s -1 and from 0.54 to 0.18 mm h -1 , respectively. On the basis of all measurements, the average value of the decoupling coefficient was 0.25. During continuous soil water shortage a proportional reduction was observed in predawn leaf water potential and in daily maximum values of stomatal conductance, canopy transpiration and decoupling coefficient. The results showed that water vapour exchange in this canopy is strongly dominated by the regional vapour pressure deficit and that canopy transpiration is controlled mainly by stomatal conductance. On a seasonal basis, stomatal conductance and canopy transpiration were mainly related to predawn leaf water potential and, thus, to soil moisture and rainfall. Good results were obtained with a multiplicative empirical model that uses values of photosynthetically active radiation, vapour pressure deficit and predawn leaf water potential to estimate stomatal conductance.

Trees, 2000

... Marcelo S. Mielke · Marco A. Oliva Nairam F. de Barros · Ricardo M. Penchel Carlos A. Martine... more ... Marcelo S. Mielke · Marco A. Oliva Nairam F. de Barros · Ricardo M. Penchel Carlos A. Martinez · Sebastião da Fonseca Auro C. de Almeida ... of gs, A, WUE and Ci/Ca, a multiple linear regression model, which was successfully used by McCaughey and Iacobelli (1994), was used ...