José Costa - Academia.edu (original) (raw)

Papers by José Costa

Hepatology, 2009

N ational Institutes of Health (NIH) consensus and stateof-the-science statements are prepared by... more N ational Institutes of Health (NIH) consensus and stateof-the-science statements are prepared by independent panels of health professionals and public representatives on the basis of 1) the results of a systematic literature review prepared under contract with the Agency for Healthcare Research and Quality; 2) presentations by investigators working in areas relevant to the conference questions during a 2-day public session; 3) questions and statements from conference attendees during open discussion periods that are part of the public session; and 4) closed deliberations by the panel during the remainder of the second day and morning of the third. This statement is an independent report of the panel and is not a policy statement of the National Institutes of Health or the U.S. government. The following statement is an abridged version of the panel's report, which is available in full at http: //consensus.nih.gov/2010/lactosestatement.htm.

ACM Transactions on Sensor Networks, 2006

Accurate, distributed localization algorithms are needed for a wide variety of wireless sensor ne... more Accurate, distributed localization algorithms are needed for a wide variety of wireless sensor network applications. This paper introduces a scalable, distributed weighted-multidimensional scaling (dwMDS) algorithm that adaptively emphasizes the most accurate range measurements and naturally accounts for communication constraints within the sensor network. Each node adaptively chooses a neighborhood of sensors, updates its position estimate by minimizing a local cost function and then passes this update to neighboring sensors. Derived bounds on communication requirements provide insight on the energy efficiency of the proposed distributed method versus a centralized approach. For received signal-strength (RSS) based range measurements, we demonstrate via simulation that location estimates are nearly unbiased with variance close to the Cramér-Rao lower bound. Further, RSS and time-of-arrival (TOA) channel measurements are used to demonstrate performance as good as the centralized maximum-likelihood estimator (MLE) in a real-world sensor network.

Diagnostic Molecular Pathology, 1995

We have developed and tested a rapid and sensitive method of detecting expansion of T-cell clones... more We have developed and tested a rapid and sensitive method of detecting expansion of T-cell clones using the polymerase chain reaction (PCR) and a single set of consensus primers for the V and J regions to amplify rearranged T-cell receptor-gamma (TCR-gamma) genes. Monoclonality was continued in all of the 18 cases of T-cell neoplasms tested, but not in reactive lymphadenopathy, non-Hodgkin's B lymphomas, and Hodgkin's disease. PCR analysis, using the primer sequence outlined in this study, had an overall specificity of 100% when compared with Southern blot analysis. No false-negative results were observed, certainly owing to the choice of consensus primers and to the control of PCR reactions on agarose gels before testing for clonality by separation of PCR products on polyacrylamide gels. This method for the detection of T-cell monoclonality can be especially useful in cases that are diagnostically problematic with standard histological and immunological analysis and in cases where the material available is limited.

Results on large-signal modeling efforts for a novel MOSFET technology for L-band RF applications... more Results on large-signal modeling efforts for a novel MOSFET technology for L-band RF applications are presented. A parameter extraction procedure which yields accurate RF MOS large-signal models using DC and S-parameter data is presented along with a comparison of measured and modeled class-B amplifier, mixer, and S-parameter data.>

A silicon-based technology is presented which integrates passive components with a silicon power ... more A silicon-based technology is presented which integrates passive components with a silicon power MOSFET for use in integrated power amplifiers at UHF, VHF, and RF frequencies. This low-cost process incorporates capacitors, inductors, resistors, ground vias, transmission lines, and an ESD protection diode. A design library containing models and layouts for the active and passive components was compiled.

We describe a method of polynomial simulation to calculate switching activities in a general-dela... more We describe a method of polynomial simulation to calculate switching activities in a general-delay combinational logic circuit. This method is a generalization of the exact signal probability evaluation method due to Parker and McCluskey, which as been extended to handle temporal correlation and arbitrary transport delays.

Proceedings of The National Academy of Sciences, 1992

A wild-type p53 gene under control of the metallothionein MT-1 promoter was stably transfected in... more A wild-type p53 gene under control of the metallothionein MT-1 promoter was stably transfected into human colon tumor-derived cell line EB. Repeated inductions of the metallothionein wild-type p53 gene with zinc chloride results in progressive detachment of wild-type p53 cells grown on culture dishes. Examination at both the light and electron microscopic level revealed that cells expressing wild-type p53 developed morphological features of apoptosis. DNA from both attached and detached cells was degraded into a ladder of nucleosomal-sized fragments. Expression of wild-type p53 inhibited colony formation in soft agar and tumor formation in nude mice. Furthermore, established tumors in nude mice underwent regression if wild-type p53 expression was subsequently induced. Regressing tumors showed histological features of apoptosis. Thus, regression of these tumors was the result of apoptosis occurring in vivo. Apoptosis may be a normal part of the terminal differentiation program of colonic epithelial cells. Our results suggest that wild-type p53 could play a critical role in this process.

Nucleic Acids Research, 1996

PCR has become a powerful tool for genetic analysis and many applications for gene sequence quant... more PCR has become a powerful tool for genetic analysis and many applications for gene sequence quantitation are based on this technology (1-3). Standardized reaction conditions require accurate quantitation of input DNA as well as optimization of chemical and cycling parameters. In this study we discuss PicoGreen™ (Molecular Probes, Eugene, OR) fluorescence enhancement as a useful assay for template DNA quantitation and PCR product formation.

Annals of Surgery, 1982

Between May 1975 and April 1981, 43 adult patients with high-grade soft tissue sarcomas of the ex... more Between May 1975 and April 1981, 43 adult patients with high-grade soft tissue sarcomas of the extremities were prospectively randomized to receive either amputation at or above the joint proximal to the tumor, including all involved muscle groups, or to receive a limb-sparing resection plus adjuvant radiation therapy. The limb-sparing resection group received wide local excision followed by 5000 rads to the entire anatomic area at risk for local spread and 6000 to 7000 rads to the tumor bed. Both randomization groups received postoperative chemotherapy with doxorubicin (maximum cumulative dose 550 mg/m2), cyclophosphamide, and high-dose methotrexate. Twenty-seven patients randomized to receive limb-sparing resection and radiotherapy, and 16 received amputation (randomization was 2:1). There were four local recurrences in the limb-sparing group and none in the amputation group (p1 = 0.06 generalized Wilcoxon test). However, there were no differences in disease-free survival rates (71% and 78% at five years; p2 = 0.75) or overall survival rates (83% and 88% at five years; p2 = 0.99) between the limb-sparing group and the amputation treatment groups. Multivariate analysis indicated that the only correlate of local recurrence was the final margin of resection. Patients with positive margins of resection had a higher likelihood of local recurrence compared with those with negative margins (p1 less than 0.0001) even when postoperative radiotherapy was used. A simultaneous prospective randomized study of postoperative chemotherapy in 65 patients with high-grade soft-tissue sarcomas of the extremities revealed a marked advantage in patients receiving chemotherapy compared with those without chemotherapy in three-year continuous disease-free (92% vs. 60%; p1 = 0.0008) and overall survival (95% vs. 74%; p1 = 0.04). Thus limb-sparing surgery, radiation therapy, and adjuvant chemotherapy appear capable of successfully treating the great majority of adult patients with soft tissue sarcomas of the extremity.

Hepatology, 2009

N ational Institutes of Health (NIH) consensus and stateof-the-science statements are prepared by... more N ational Institutes of Health (NIH) consensus and stateof-the-science statements are prepared by independent panels of health professionals and public representatives on the basis of 1) the results of a systematic literature review prepared under contract with the Agency for Healthcare Research and Quality; 2) presentations by investigators working in areas relevant to the conference questions during a 2-day public session; 3) questions and statements from conference attendees during open discussion periods that are part of the public session; and 4) closed deliberations by the panel during the remainder of the second day and morning of the third. This statement is an independent report of the panel and is not a policy statement of the National Institutes of Health or the U.S. government. The following statement is an abridged version of the panel's report, which is available in full at http: //consensus.nih.gov/2010/lactosestatement.htm.

ACM Transactions on Sensor Networks, 2006

Accurate, distributed localization algorithms are needed for a wide variety of wireless sensor ne... more Accurate, distributed localization algorithms are needed for a wide variety of wireless sensor network applications. This paper introduces a scalable, distributed weighted-multidimensional scaling (dwMDS) algorithm that adaptively emphasizes the most accurate range measurements and naturally accounts for communication constraints within the sensor network. Each node adaptively chooses a neighborhood of sensors, updates its position estimate by minimizing a local cost function and then passes this update to neighboring sensors. Derived bounds on communication requirements provide insight on the energy efficiency of the proposed distributed method versus a centralized approach. For received signal-strength (RSS) based range measurements, we demonstrate via simulation that location estimates are nearly unbiased with variance close to the Cramér-Rao lower bound. Further, RSS and time-of-arrival (TOA) channel measurements are used to demonstrate performance as good as the centralized maximum-likelihood estimator (MLE) in a real-world sensor network.

Diagnostic Molecular Pathology, 1995

We have developed and tested a rapid and sensitive method of detecting expansion of T-cell clones... more We have developed and tested a rapid and sensitive method of detecting expansion of T-cell clones using the polymerase chain reaction (PCR) and a single set of consensus primers for the V and J regions to amplify rearranged T-cell receptor-gamma (TCR-gamma) genes. Monoclonality was continued in all of the 18 cases of T-cell neoplasms tested, but not in reactive lymphadenopathy, non-Hodgkin's B lymphomas, and Hodgkin's disease. PCR analysis, using the primer sequence outlined in this study, had an overall specificity of 100% when compared with Southern blot analysis. No false-negative results were observed, certainly owing to the choice of consensus primers and to the control of PCR reactions on agarose gels before testing for clonality by separation of PCR products on polyacrylamide gels. This method for the detection of T-cell monoclonality can be especially useful in cases that are diagnostically problematic with standard histological and immunological analysis and in cases where the material available is limited.

Results on large-signal modeling efforts for a novel MOSFET technology for L-band RF applications... more Results on large-signal modeling efforts for a novel MOSFET technology for L-band RF applications are presented. A parameter extraction procedure which yields accurate RF MOS large-signal models using DC and S-parameter data is presented along with a comparison of measured and modeled class-B amplifier, mixer, and S-parameter data.>

A silicon-based technology is presented which integrates passive components with a silicon power ... more A silicon-based technology is presented which integrates passive components with a silicon power MOSFET for use in integrated power amplifiers at UHF, VHF, and RF frequencies. This low-cost process incorporates capacitors, inductors, resistors, ground vias, transmission lines, and an ESD protection diode. A design library containing models and layouts for the active and passive components was compiled.

We describe a method of polynomial simulation to calculate switching activities in a general-dela... more We describe a method of polynomial simulation to calculate switching activities in a general-delay combinational logic circuit. This method is a generalization of the exact signal probability evaluation method due to Parker and McCluskey, which as been extended to handle temporal correlation and arbitrary transport delays.

Proceedings of The National Academy of Sciences, 1992

A wild-type p53 gene under control of the metallothionein MT-1 promoter was stably transfected in... more A wild-type p53 gene under control of the metallothionein MT-1 promoter was stably transfected into human colon tumor-derived cell line EB. Repeated inductions of the metallothionein wild-type p53 gene with zinc chloride results in progressive detachment of wild-type p53 cells grown on culture dishes. Examination at both the light and electron microscopic level revealed that cells expressing wild-type p53 developed morphological features of apoptosis. DNA from both attached and detached cells was degraded into a ladder of nucleosomal-sized fragments. Expression of wild-type p53 inhibited colony formation in soft agar and tumor formation in nude mice. Furthermore, established tumors in nude mice underwent regression if wild-type p53 expression was subsequently induced. Regressing tumors showed histological features of apoptosis. Thus, regression of these tumors was the result of apoptosis occurring in vivo. Apoptosis may be a normal part of the terminal differentiation program of colonic epithelial cells. Our results suggest that wild-type p53 could play a critical role in this process.

Nucleic Acids Research, 1996

PCR has become a powerful tool for genetic analysis and many applications for gene sequence quant... more PCR has become a powerful tool for genetic analysis and many applications for gene sequence quantitation are based on this technology (1-3). Standardized reaction conditions require accurate quantitation of input DNA as well as optimization of chemical and cycling parameters. In this study we discuss PicoGreen™ (Molecular Probes, Eugene, OR) fluorescence enhancement as a useful assay for template DNA quantitation and PCR product formation.

Annals of Surgery, 1982

Between May 1975 and April 1981, 43 adult patients with high-grade soft tissue sarcomas of the ex... more Between May 1975 and April 1981, 43 adult patients with high-grade soft tissue sarcomas of the extremities were prospectively randomized to receive either amputation at or above the joint proximal to the tumor, including all involved muscle groups, or to receive a limb-sparing resection plus adjuvant radiation therapy. The limb-sparing resection group received wide local excision followed by 5000 rads to the entire anatomic area at risk for local spread and 6000 to 7000 rads to the tumor bed. Both randomization groups received postoperative chemotherapy with doxorubicin (maximum cumulative dose 550 mg/m2), cyclophosphamide, and high-dose methotrexate. Twenty-seven patients randomized to receive limb-sparing resection and radiotherapy, and 16 received amputation (randomization was 2:1). There were four local recurrences in the limb-sparing group and none in the amputation group (p1 = 0.06 generalized Wilcoxon test). However, there were no differences in disease-free survival rates (71% and 78% at five years; p2 = 0.75) or overall survival rates (83% and 88% at five years; p2 = 0.99) between the limb-sparing group and the amputation treatment groups. Multivariate analysis indicated that the only correlate of local recurrence was the final margin of resection. Patients with positive margins of resection had a higher likelihood of local recurrence compared with those with negative margins (p1 less than 0.0001) even when postoperative radiotherapy was used. A simultaneous prospective randomized study of postoperative chemotherapy in 65 patients with high-grade soft-tissue sarcomas of the extremities revealed a marked advantage in patients receiving chemotherapy compared with those without chemotherapy in three-year continuous disease-free (92% vs. 60%; p1 = 0.0008) and overall survival (95% vs. 74%; p1 = 0.04). Thus limb-sparing surgery, radiation therapy, and adjuvant chemotherapy appear capable of successfully treating the great majority of adult patients with soft tissue sarcomas of the extremity.