Characteristic of the ultrawideband electromagnetic radiation generated by PCSS

A novel ultra-wideband electromagnetic pulse generating method based on the photoconductive semiconductor switches (PCSS) is presented. Gallium arsenide is used to develop the PCSS for an ultrashort electromagnetic pulse source. The pulse generated by such PCSS is within picosecond (ps) time scale, and can yield power pulse with an voltage over 10 kV. The experimental results show that the pulses are stable, with the peak-peak amplitude change of 6% and the time jitter within several picoseconds. The radiations of the PCSS triggered by the picosecond laser and fenitosecond laser pulse series illustrate that the electromagnetic pulses would have high repetition of more than 80 MHz and frequency bandwidth of DC-6 GHz. The radiations of "lock-on " mode of the PCSS are also analyzed here. (c) 2007 Wiley Periodicals, Inc.

A forward and backward secure key management in wireless sensor networks for PCS/SCADA

Process Control Systems (PCSs) or Supervisory Control and Data Acquisition (SCADA) systems have recently been added to the already wide collection of wireless sensor networks applications. The PCS/SCADA environment is somewhat more amenable to the use of heavy cryptographic mechanisms such as public key cryptography than other sensor application environments. The sensor nodes in the environment, however, are still open to devastating attacks such as node capture, which makes designing a secure key management challenging. In this paper, a key management scheme is proposed to defeat node capture attack by offering both forward and backward secrecies. Our scheme overcomes the pitfalls which Nilsson et al.'s scheme suffers from, and is not more expensive than their scheme.

Mitigating sandwich attacks against a secure key management scheme in wireless sensor networks for PCS/SCADA

Alzaid et al. proposed a forward & backward secure key management scheme in wireless sensor networks for Process Control Systems (PCSs) or Supervisory Control and Data Acquisition (SCADA) systems. The scheme, however, is still vulnerable to an attack called the sandwich attack that can be launched when the adversary captures two sensor nodes at times t1 and t2, and then reveals all the group keys used between times t1 and t2. In this paper, a fix to the scheme is proposed in order to limit the vulnerable time duration to an arbitrarily chosen time span while keeping the forward and backward secrecy of the scheme untouched. Then, the performance analysis for our proposal, Alzaid et al.’s scheme, and Nilsson et al.’s scheme is given.

A survey of patients' experience of pain and other symptoms while receiving care from palliative care services

Context In Australia, patients at the end of life with complex symptoms and needs are often referred to palliative care services (PCSs), but little is known about the symptoms of patients receiving palliative care in different settings. Objective To explore patients’ levels of pain and other symptoms while receiving care from PCSs. Method PCSs registered through Australia's national Palliative Care Outcomes Collaboration (PCOC) were invited to participate in a survey between 2008 and 2011. Patients (or if unable, a proxy) were invited to complete the Palliative Care Outcome Scale. Results Questionnaires were completed for 1800 patients. One-quarter of participants reported severe pain, 20% reported severe ‘other symptoms’, 20% reported severe patient anxiety, 45% reported severe family anxiety, 66% experienced depressed feelings and 19% reported severe problems with self-worth. Participants receiving care in major cities reported higher levels of depressed feelings than participants in inner regional areas. Participants receiving care in community and combined service settings reported higher levels of need for information, more concerns about wasted time, and lower levels of family anxiety and depressed feelings when compared to inpatients. Participants in community settings had lower levels of concern about practical matters than inpatients. Conclusions Patients receiving care from Australian PCSs have physical and psychosocial concerns that are often complex and rated as ‘severe’. Our findings highlight the importance of routine, comprehensive assessment of patients’ concerns and the need for Specialist Palliative Care clinicians to be vigilant in addressing pain and other symptoms in a timely, systematic and holistic manner, whatever the care setting.

Coleta Seletiva Solidária de resíduos recicláveis dirigida à rede estadual de ensino do Rio de Janeiro - estudo de caso.

O aumento da demanda de água, energia, bem como a mudança na composição e na quantidade dos resíduos, associados aos impactos socioambientais que eles provocam, tornaram-se um dos grandes desafios atuais para a sociedade e, em particular, para as escolas públicas. Nesse contexto, o governo do estado do Rio de Janeiro, dentro de seu Plano Estadual de Gerenciamento Integrado de Resíduos Sólidos, criou o Programa Coleta Seletiva Solidária (PCSS), em outubro de 2009, realizado em parceria entre o Instituto Estadual do Ambiente (INEA), a Universidade do Estado do Rio de Janeiro (UERJ) e a Secretaria de Estado de Educação (SEEDUC). Este Programa assessora a implantação da Coleta Seletiva Solidária (CSS) de materiais recicláveis nos municípios do estado. O eixo-escolas, uma das suas linhas de ações, assessora a implantação da CSS na rede estadual, conforme determina o Decreto Estadual 40.645/07. Considerando os problemas relacionados aos resíduos e a exigência legal, boa parte das escolas estaduais não implantaram ainda a Coleta Seletiva Solidária, por diversos fatores. O objetivo da pesquisa é estudar o modelo de Coleta Seletiva proposto pelo PCSS nas escolas da rede estadual de ensino do Rio de Janeiro. Como estudo de caso, esse modelo foi aplicado no Colégio Estadual Souza Aguiar (CESA). Utilizou-se da pesquisa-ação como abordagem metodológica e o instrumento de coleta de dados foi o questionário dirigido aos participantes das oficinas de capacitação na UERJ. No CESA foram aplicados questionários aos alunos e acompanhado o processo de implantação da CSS através da observação participante. Conclui-se que os resultados da pesquisa não podem ser generalizados para toda a rede estadual de ensino do Rio de Janeiro. Contudo, ele possibilitou identificar questões importantes e sugerir recomendações para o aperfeiçoamento do modelo estudado. Destaca-se a importância de formalizar o compromisso institucional dos dirigentes das escolas com a implantação da CSS, contribuindo com a formação de cidadãos comprometidos com a sustentabilidade socioambiental do estado do Rio de Janeiro.

CHARACTERIZATION OF PHOTOCONDUCTIVE SEMICONDUCTOR SWITCHES UNDER NONLINEAR MODE CONDITION

A photoconductive semiconductor switch (PCSS) would work in a nonlinear mode under high biased electrical field. The experimental results of nonlinear critical state have shown that both the biased voltage and the laser energy may have working thresholds to turn on the nonlinear modes. The relation between the biased voltage (aid the laser energy is inverse ratio, i.e., higher biased field need lower laser energy for nonlinear mode, and vise versa. At the nonlinear critical point, the output of PCSS is unstable, as both the linear and nonlinear pulse may occur. As the laser energy and biased field increase, the PCSS would work in the nonlinear mode steadily. (C) 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 56-59 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOT 10.1002/mop.24001

Integrated analysis of halogenated organic pollutants in sub-millilitre volumes of venous and umbilical cord blood sera

A rapid, robust and economical method for the analysis of persistent halogenated organic compounds in small volumes of human serum and umbilical cord blood is described. The pollutants studied cover a broad range of molecules of contemporary epidemiological and legislative concern, including polychlorobiphenyls (PCBs), polychlorobenzenes (CBs), hexachlorocyclohexanes (HCHs), DDTs, polychlorostyrenes (PCSs) and polybromodiphenyl ethers (PBDEs). Extraction and clean-up with n-hexane and concentrated sulphuric acid was followed with analysis by gas chromatography coupled to electron capture (GC-ECD) and GC coupled to negative ion chemical ionisation mass spectrometry (GC-NICI-MS). The advantages of this method rest in the broad range of analytes and its simplicity and robustness, while the use of concentrated sulphuric acid extraction/clean-up destroys viruses that may be present in the samples. Small volumes of reference serum between 50 and 1000 μL were extracted and the limits of detection/quantification and repeatability were determined. Recoveries of spiked compounds for the extraction of small volumes (≥300 μL) of the spiked reference serum were between 90% and 120%. The coefficients of variation of repeatability ranged from 0.1-14%, depending on the compound. Samples of 4-year-old serum and umbilical cord blood (n = 73 and 40, respectively) from a population inhabiting a village near a chloro-alkali plant were screened for the above-mentioned halogenated pollutants using this method and the results are briefly described. © 2010 Springer-Verlag.

Stratification of high-risk prostate cancer into prognostic categories: a European multi-institutional study

BACKGROUND High-risk prostate cancer (PCa) is an extremely heterogeneous disease. A clear definition of prognostic subgroups is mandatory. OBJECTIVE To develop a pretreatment prognostic model for PCa-specific survival (PCSS) in high-risk PCa based on combinations of unfavorable risk factors. DESIGN, SETTING, AND PARTICIPANTS We conducted a retrospective multicenter cohort study including 1360 consecutive patients with high-risk PCa treated at eight European high-volume centers. INTERVENTION Retropubic radical prostatectomy with pelvic lymphadenectomy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Two Cox multivariable regression models were constructed to predict PCSS as a function of dichotomization of clinical stage (< cT3 vs cT3-4), Gleason score (GS) (2-7 vs 8-10), and prostate-specific antigen (PSA; ≤ 20 ng/ml vs > 20 ng/ml). The first "extended" model includes all seven possible combinations; the second "simplified" model includes three subgroups: a good prognosis subgroup (one single high-risk factor); an intermediate prognosis subgroup (PSA >20 ng/ml and stage cT3-4); and a poor prognosis subgroup (GS 8-10 in combination with at least one other high-risk factor). The predictive accuracy of the models was summarized and compared. Survival estimates and clinical and pathologic outcomes were compared between the three subgroups. RESULTS AND LIMITATIONS The simplified model yielded an R(2) of 33% with a 5-yr area under the curve (AUC) of 0.70 with no significant loss of predictive accuracy compared with the extended model (R(2): 34%; AUC: 0.71). The 5- and 10-yr PCSS rates were 98.7% and 95.4%, 96.5% and 88.3%, 88.8% and 79.7%, for the good, intermediate, and poor prognosis subgroups, respectively (p = 0.0003). Overall survival, clinical progression-free survival, and histopathologic outcomes significantly worsened in a stepwise fashion from the good to the poor prognosis subgroups. Limitations of the study are the retrospective design and the long study period. CONCLUSIONS This study presents an intuitive and easy-to-use stratification of high-risk PCa into three prognostic subgroups. The model is useful for counseling and decision making in the pretreatment setting.