bluuebunny/crossref_metadata_2025 huggingface dataset:
Incontinence improves in older women after intensive pelvic floor muscle training: An assessor‐blinded randomized controlled trial
Authors: Sherburn Margaret , Bird Margaret , Carey Marcus , Bø Kari , Galea Mary P.
Published: January 2011

Aims

To test the hypotheses that high intensity pelvic floor muscle training (PFMT) is effective in relief of stress urinary incontinence in community dwelling older women, and that intense PFMT improves stress urinary incontinence more than bladder training (BT) in this population.

Methods

A two‐center, assessor‐blinded randomized controlled trial of 20 weeks duration with two active intervention arms: PFMT and BT. Assessments and interventions were undertaken at two metropolitan tertiary hospitals. Participants were community dwelling women over 65 years of age with urodynamic stress incontinence. Primary outcome measure was urinary leakage during a cough stress test. Secondary outcome measures included symptoms and bother (ICIQ‐UI SF), participant global perception of change, leakage episodes (7‐day accident diary), degree of “bother” (VAS) and health related quality of life (AQoL).

Results

Eighty‐three Caucasian women, 71.8 (SD 5.3) years participated in the study. Both groups improved over the intervention period; however, the PFMT group reported significantly lower amounts of leakage on the stress test [PFMT median 0.0 g, 95% CI: 0.2–0.9; BT median 0.3 g, 95% CI: 0.2–1.7, P = 0.006], improved symptoms and bother [PFMT mean 5.9, 95% CI: 4.8–7.1; BT group mean 8.5, 95% CI: 7.1–9.9 and greater perception of change [PFMT 28 (73.6%); BT 12 (36.4%) (P = 0.002)] after 5 months than the BT group.

Conclusions

High intensity PFMT is effective in managing stress urinary incontinence and is more effective than BT in healthy older women. Neurourol. Urodynam. 30:317–324, 2011. © 2011 Wiley‐Liss, Inc.
Quality of life in elderly men with aging symptoms and lower urinary tract symptoms (LUTS)
Authors: Perchon Lygia F.G. , Pintarelli Vitor L. , Bezerra Edson , Thiel Marcelo , Dambros Miriam
Published: January 2011

Aims

The aims of this study were to investigate quality of life (QoL) due to physical and psychological changes occurring in elderly men and to identify associated factors between lower urinary tract symptoms (LUTS) and aging male symptoms (ADAM).

Materials and Methods

This was a case–control study whereby 200 elderly men were recruited from the community and the Urology and Geriatrics ambulatories. Subjects were asked to fill out the Aging Male Symptoms Scale (AMS), World Health Organization Quality of Life‐BREF and ‐OLD, and IPSS questionnaires. Participants were classified in two groups according to IPSS: group I (moderate to severe symptoms) and group II (mild symptoms).

Results

The AMS scale and both QoL questionnaires of group I showed significantly worse median scores in all parameters. The average somatic and sexual subscore was significantly higher in group I (P < 0.0005). The social and environmental domains presented the most significant differences (P < 0.0005) in both questionnaires, and the mean of the WHOQOL‐OLD score was significantly lower in group I (P < 0.0005).

Conclusions

Moderate to severe ADAM and LUTS impact significantly all parameters of HRQOL and generic QoL proposed by the WHO. There was correlation between severity of LUTS and severity of the following ADAM: depression, feeling burnt out, decline of feeling of general well‐being, joint and body complaints, insomnia, weakness of muscles, feeling that the peak had passed, decrease of sexual performance, and decrease of morning erections. 30:515–519, 2011. © 2011 Wiley‐Liss, Inc.
Brain response provoked by different bladder volumes: A near infrared spectroscopy study
Authors: Matsumoto Shinya , Ishikawa Akira , Matsumoto Shinichi , Homma Yukio
Published: January 2011

Aims

In order to understand frontal lobe responses in bladder sensation in healthy subjects, we examined the cortical localization of response to the different bladder volumes.

Methods

Frontal blood flow was measured non‐invasively in 24 resting adults using multi‐channel near infrared spectroscopy (NIRS). Changes in bladder volume were induced by infusing and releasing water from the bladder. Two states of bladder sensation have been induced, “first desire to void” and “strong desire to void.

Results

NIRS analysis revealed that cerebral responses to bladder sensation were associated with increased levels of oxy‐hemoglobin in the bilateral frontal cortex. The responses became stronger in the state of strong desire to void at enlarged bladder volume (P < 0.01). These results indicate that bilateral frontal areas are involved in bladder perception related to increased urine volumes in adults.

Conclusions

The dynamic changes in cerebral blood oxygenation were similar to those assessed in other methodologies such as f‐MRI and PET. This result suggests that NIRS study might be available for investigating the mutual relationship between bladder and brain in patients suffering from neurological problems and urinary tract symptoms. 30:529–535, 2011. © 2011 Wiley‐Liss, Inc.
The association of changes in opening detrusor pressure with the resolution of overactive bladder symptoms after repair of pelvic organ prolapse
Authors: Basu Maya , Duckett Jonathan
Published: January 2011

Aims

To evaluate whether changes in opening detrusor pressure (ODP) are associated with resolution of overactive bladder symptoms in women undergoing surgical correction of pelvic organ prolapse.

Methods

Forty women with DO and OAB together with anterior wall prolapse who underwent a repair between 2003 and 2007 were studied. Each woman was assessed pre‐ and post‐operatively with a clinical assessment and cystometry. Opening pressures were recorded pre‐ and post‐operatively for each patient by retrospective review of the pressure flow traces. Patients were divided into those who experienced resolution of OAB symptoms and those with persistent OAB symptoms. Wilcoxon matched pairs signed rank test was used to assess any change in opening pressures between these groups.

Results

Resolution of urgency with an anterior repair was associated with a significant fall in ODP from a mean of 27.9 to 11.7 cmH2O (P = 0.01). There was no significant pre‐operative difference in ODP between women in whom urgency resolved and those in whom it did not.

Conclusion

These results suggest that a fall in ODP is associated with resolution of urgency in women undergoing prolapse surgery. This may imply that decreased urethral resistance is of importance in symptom resolution. 30:595–598, 2011. © 2011 Wiley‐Liss, Inc.
A decomposition for total‐coloring partial‐grids and list‐total‐coloring outerplanar graphs
Authors: Machado Raphael C. S. , de Figueiredo Celina M. H.
Published: February 2011

The total chromatic number χT(G) is the least number of colors sufficient to color the elements (vertices and edges) of a graph G in such a way that no incident or adjacent elements receive the same color. In the present work, we obtain two results on total‐coloring. First, we extend the set of partial‐grids classified with respect to the total‐chromatic number, by proving that every 8‐chordal partial‐grid of maximum degree 3 has total chromatic number 4. Second, we prove a result on list‐total‐coloring biconnected outerplanar graphs. If for each element x of a biconnected outerplanar graph G there exists a set Lx of colors such that |Luw| = max{deg(u) + 1, deg(w) + 1} for each edge uw and |Lv| = 7 − δdeg(v),3 − 2δdeg(v),2 (where δi,j = 1 if i = j and δi,j = 0 if i ≠ j) for each vertex v, then there is a total‐coloring π of graph G such that π(x) ∈ Lx for each element x of G. The technique used in these two results is a decomposition by a cutset of two adjacent vertices, whose properties are discussed in the article. © 2011 Wiley Periodicals, Inc. NETWORKS, 2011
Periostitis and osteolysis in a medieval skeleton from South‐West Hungary: (Leprosy, treponematosis, tuberculosis or hypertrophic osteoarthropathy) A diagnostic challenge!
Authors: Christensen Tina , Martínez‐Lavín Manuel , Pineda Carlos
Published: January 2011

This paper uses macroscopic and radiological examinations to provide differential diagnoses of pathological lesions in the well‐preserved skeleton of a young male from the medieval site of Zalavár in South‐West Hungary. Macroscopic inspection of the skeleton revealed conspicuous thickening of the tibiae and fibulae with ‘tree bark’ appearance of the cortex. Periosteal proliferations are also found on the calcanea and on the posterior part of the femora. The metatarsals showed bony proliferation and bone dissolution. No alteration of the axial skeleton or the skull was noted. Radiographs showed thickening of the cortex of tubular bones due to a multilayered type of periosteal apposition. The likelihood of these symptoms being the result of melorheostosis, hypervitaminosis A, fluorosis, thyroid acropachy, endosteal hyperostosis, tuberculosis (TB), hypertrophic osteoarthropathy (HOA), treponematosis and leprosy is reviewed. None completely explains the entire spectrum of pathological lesions in the current individual, but the individual may have suffered from two co‐existent diseases. As a clinical entity, the changes in the metatarsals are compatible with leprosy, whereas the periosteal proliferations of the lower limbs point to a diagnosis of HOA as a secondary syndrome. Thus, a combination of leprosy and TB is suggested as a potential diagnosis. Although not definitive, our differential diagnosis was able to exclude a number of conditions producing periosteal apposition. Copyright © 2011 John Wiley & Sons, Ltd.
The biological and clinical impact of inhibition of NF‐κB‐initiated apoptosis in diffuse large B cell lymphoma (DLBCL)
Authors: Bavi Prashant , Uddin Shahab , Bu Rong , Ahmed Maqbool , Abubaker Jehad , Balde Valorie , Qadri Zeeshan , Ajarim Dahish , Al‐Dayel Fouad , Hussain Azhar R , Al‐Kuraya Khawla S.
Published: February 2011

NF‐κB is frequently over‐expressed in a variety of non‐Hodgkin's lymphomas (NHLs) and has been implicated in lymphomagenesis; however, its role in diffuse large B cell lymphoma (DLBCL) as a prognostic biomarker has not been fully elucidated. Therefore, we investigated the role of NF‐κB and its association with clinicopathological features in a tissue microarray cohort of 230 DLBCL patient samples. We then elucidated the role of NF‐κB inhibition on cell viability and apoptosis in vitro, using DLBCL cell lines. Using immunohistochemistry, NF‐κB was detected in 25.6% (52/203) DLBCL tumours, was associated with activated B cell (ABC) phenotype (p = 0.0054), Epstein–Barr virus (EBV; p = 0.0080) and over‐expression of the anti‐apoptotic marker XIAP (p = 0.0013). DLBCL cases with nuclear expression of NF‐κB showed a significantly poorer overall survival as compared to those without NF‐κB expression (p = 0.0236). In a multivariate analysis using a Cox proportional hazard model for IPI and NF‐κB expression, the relative risk was 2.97 for high NF‐κB expression (95% CI 1.27–6.94; p = 0.0113) and 7.55 for the high‐IPI group (95% CI 3.34–18.35; p < 0.0001). In vitro, Bay 11‐7085 inhibited constitutively active NF‐κB expression in a dose‐dependent manner and inhibition of NF‐κB also down‐regulated expression of the downstream target gene products Bcl‐2, Bcl‐XL (BCL2L1), XIAP and Survivin, leading to apoptosis via activation of the mitochondrial apoptotic pathway. NF‐κB over‐expression was found to be an independent prognostic marker for poor survival in DLBCL. Altogether, these results suggest that NF‐κB may be a useful prognostic biomarker and a potential target for therapeutic intervention in DLBCL. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Cytomegalovirus sinusitis in a child with chronic myelogenous leukemia following bone marrow transplantation
Authors: Rayes Ahmad , Sahni Kiren , Hanna Christian , Suryadevara Manika , Goyal Parul , Cherrick Irene
Published: February 2011

Cytomegalovirus (CMV) is a common opportunistic pathogen. CMV sinusitis has been described in acquired immunodeficiency syndrome (AIDS) patients, but not in other immune compromising conditions. In this report, we describe CMV sinusitis in a child with chronic myelogenous leukemia (CML) following bone marrow transplantation. Pediatr Blood Cancer 2011;56:1140–1142. © 2011 Wiley‐Liss, Inc.
Water absorption behavior of PALF/GF hybrid polyester composites
Authors: Devi L. Uma , Bhagawan S.S. , Nair K.C. Manikandan , Thomas S.
Published: February 2011

The water absorption characteristics of pineapple leaf fiber (PALF)/glass fiber (GF) hybrid polyester(PER) composites, and chemically modified PALF/polyester composites were evaluated by immersion in distilled water at 28, 60, and 90°C. The diffusion properties of the intimately mixed (IM) and the layered hybrid composite GPG (Glass skin and PALF core) of different PALF/GF ratio at the three temperatures were compared in order to identify the environmental ageing mechanism at different temperatures. The effect of temperature on the kinetics and thermodynamics of diffusion were also examined. The water uptake of both IM and GPG hybrid composites was decreased with increase in glass fiber content; the lowest water uptake was observed for 0.46 Vf GF hybrid composite. Among the chemically modified composites, vinyl tri 2‐methoxy ethoxy silane treated composites showed the lowest water uptake. Finally, parameters like diffusion, sorption, and permeability coefficients were determined. It was observed that equilibrium water uptake is dependent on the nature of the composite and temperature. Experimental results were also compared with theoretical predictions. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Electro conductivities of well‐dispersed PMMA‐g‐MWNTs/6FDA‐based polyimide composites: Effect of chemical structure
Authors: Im Hyungu , Yun Sungjin , Kim Jooheon
Published: February 2011

PMMA (polymethylmethacrylate), which is miscible with hexafluoropropane dianhydride (6FDA)‐based polyimide, was grafted onto MWNTs surfaces to enhance their dispersion relative to that of pristine MWNTs. The electrical conductivity of the 6FDA‐based composite revealed percolation threshold behavior, and the 6FDA‐4,4′‐(hexafluoroisopropylidene)diamine, (6FpDA):3,5‐diaminobenzoic acid (DABA)/PMMA‐g‐MWNT composite showed a higher percolation threshold concentration and a slightly lower critical exponent compared with those of the 6FDA‐6FpDA composite. Because of the weak interaction energies between 6FDA‐6FpDA:DABA and PMMA, agglomerated domains were formed. Also, the weak interaction energies of the 6FDA‐6FpDA:DABA led to a larger reduction in the normalized transmittance compared with that seen in the 6FDA‐6FpDA composite. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Free vibration of generally laminated plates with various shapes
Authors: Yousefi P. , Kargarnovin M.H. , Hosseini‐Hashemi S.H.
Published: February 2011

This article is focused on a simple approach for determining the natural frequency and mode shape of laminated angle‐ply plates with various shapes by rectangular orthotropy. Since the boundary of the domain for all shapes are not natural to the material coordinate axes it seems appropriate to express the plate displacement amplitude in terms of a polynomial and a general shape function multiplication in the x and y coordinates. The boundary conditions considered are clamped and simply supported edges. The effect of the fiber orientation, layer number, and lamination sequence on the natural frequencies of plates is also considered. The natural frequency determinant has been generated using the classical Rayleigh‐Ritz method. The algorithm developed can be used for a wide range of different plate shape having an internal hole, internal ring support, and any aspect ratio by simple programming. The natural frequencies and mode shapes of four cases of plate shape are obtained and some results were compared with those existing in the literature and analytical solution for simply supported rectangular plates with especially orthotropy. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Studies on transport of vapor and solute molecules through polyvinyl alcohol‐based clay containing nanocomposites
Authors: Sancha Rachna , Bajpai Jaya , Bajpai Anil K.
Published: February 2011

The present study focuses on fabricating of polymer–clay nanocomposites by in situ polymerization method and investigating their permeability behavior toward vapor and liquid molecules, thus, to evaluating barrier properties of the nanocomposites. For this purpose, acrylonitrile (AN) monomer was grafted on to poly(vinyl alcohol) (PVA) chains after the addition of very low amount of fuller's earth (clay) into polymer matrix using a suitable initiator, such as potassium persulphate (KPS), and crosslinker N‐N′ methylene bisacrylamide (MBA). The prepared nanomaterials were characterized by Fourier‐Transformation infrared (FTIR) spectroscopy and wide‐angle X‐ray diffraction (WXRD) techniques. The morphological features of designed materials were studied by scanning electron microscopy. The graft materials impregnated with fuller's earth were examined for their permeability behavior by observing the permeation of solute and vapor molecules from aqueous dye solution and volatile organic solvent, respectively. The composition of the nanocomposites and the amount of fuller's earth content were found to affect the passage of solute and vapor molecules across the nanocomposite membrane. The permeation capacity was quantified by evaluating permeability parameters. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Prenatal diagnosis of congenital vascular rings and slings: sonographic features and perinatal outcome in 81 consecutive cases
Authors: Li Shengli , Luo Guoyang , Norwitz Errol R. , Wang Chenhong , Ouyang Shuyuan , Yao Yuan , Chen Congying , Wen Huaxuan , Chen Xiulan , Bi Jingru
Published: January 2011

Objective

To describe the sonographic features and perinatal outcome of congenital vascular rings diagnosed prenatally at a single tertiary care institution.

Methods

All cases of congenital vascular rings diagnosed by prenatal ultrasound between July 2005 and December 2009 were identified at a single referral center using an established perinatal database. The diagnosis was confirmed by postnatal echocardiography for live‐born infants or autopsy for terminated cases.

Results

The overall incidence of vascular ring during this 5‐year period was 0.086% (81 cases among 94 321 women undergoing perinatal ultrasound examination). Forty‐four cases had complete O‐shaped (n = 3) or U‐shaped (n = 41) vascular rings, and 37 cases had incomplete C‐shaped vascular rings (vascular slings). The most common type of vascular ring seen in 50.6% (41/81) of cases was a right aortic arch with aberrant left subclavian artery. The second most common type was a left aortic arch with an aberrant right subclavian artery [39.5% (32/81)]. Chromosomal analysis was performed prenatally in 46 pregnancies, and six cases (13.0%) of fetal aneuploidy were identified.

Conclusions

Congenital vascular rings can be diagnosed with prenatal ultrasound using the three‐vessel trachea view and subsequent fetal echocardiography with particular attention to the relationship of the aortic arches, ductal arches, and the trachea. Copyright © 2011 John Wiley & Sons, Ltd.
An Analysis of Interrelationships between Project Management and Student-Experience Constructs
Authors: Chipulu Maxwell , Ojiako Udechukwu , Ashleigh Melanie , Maguire Stuart
Published: January 2011

This article seeks to explore, through the utilization of correlational analysis, how the parameters that impact the student experience may be interrelated. We found that the experiences of students studying project management appear to be heavily influenced by e-resource provisions and the actual experiences that the students are subjected to when using virtual learning environments (VLEs). These findings support previous research acknowledging that information and communications technology (ICT) plays an important role in teaching and learning project management. Students’ experience of interpersonal skills also correlated uniquely and significantly with other constructs, supporting the premise that learning is integral to the development of interpersonal skills. Discussion surrounds the interdependency of student experiences adding to their learning and how future research should consider larger and more diverse samples to establish exactly what constructs detract and/or add to their learning in project management, which could then contribute to pedagogical discourse in other disciplines.
Accuracy of the Danish version of the ‘distress thermometer’
Authors: Bidstrup Pernille Envold , Mertz Birgitte Goldschmidt , Dalton Susanne Oksbjerg , Deltour Isabelle , Kroman Niels , Kehlet Henrik , Rottmann Nina , Gärtner Rune , Mitchell Alex J , Johansen Christoffer
Published: January 2011

Objective: Short screening instruments have been suggested to improve the detection of psychological symptoms. We examined the accuracy of the Danish version of the ‘Distress Thermometer’.

Methods: Between October 2008 and October 2009, 426 women with newly diagnosed primary breast cancer who were operated at the Breast Surgery Clinic of the Rigshospitalet, Copenhagen, were eligible for this study. Of these, 357 participated (84%) and 333 completed a questionnaire. The distress thermometer was evaluated against the ‘hospital anxiety and depression scale’ (HADS). We also examined the women's wish for referral for psychological support.

Results: A cut‐off score of 6 vs 7 (low:⩽6, high:⩾7) on the distress thermometer was optimal for confirming distress, with a sensitivity of 42%, a specificity of 93%, a positive predictive value (PPV) of 78% and a negative predictive value (NPV) of 73%. A cut‐off score of 2 vs 3 was optimal for screening, with a sensitivity of 99%, a specificity of 36%, a PPV of 47% and a NPV of 99%. Of those who were distressed using the cut‐off score of 2 vs 3 on the distress thermometer, 17% (n = 41) wished to be referred for psychological support and 57% (n = 140) potentially wanted a later referral.

Conclusion: The distress thermometer performed satisfactorily relative to the HADS in detecting distress in our study. A screening procedure in which application of the distress thermometer is a first step could be useful for identifying persons in need of support. Copyright © 2011 John Wiley & Sons, Ltd.
Pulmonary outcome of alport syndrome with familial diffuse esophageal leiomymatosis
Authors: Livnat Galit , Best Lael Anson , Guralnik Ludmila , Bentur Lea
Published: January 2011

X‐linked Alport syndrome is associated in some families with diffuse leiomyomatosis. We describe herein, the pulmonary complications and outcome of three family members (mother, daughter, and son). The three underwent esophagectomy at different ages (22 years, three years, and 15 months respectively). Their current forced expiratory volume in the first second (FEV1) ranged from 33% in the mother to 60% in the daughter and 97% in the son. It is suggested that earlier intervention may lead to improved pulmonary function tests. Pediatr. Pulmonol. 2011; 46:614–616. © 2011 Wiley‐Liss, Inc.
Respiration rate monitoring methods: A review
Authors: AL‐Khalidi F.Q. , Saatchi R. , Burke D. , Elphick H. , Tan S.
Published: January 2011

Respiration rate is an important indicator of a person's health, and thus it is monitored when performing clinical evaluations. There are different approaches for respiration monitoring, but generally they can be classed as contact or noncontact. For contact methods, the sensing device (or part of the instrument containing it) is attached to the subject's body. For noncontact approaches the monitoring is performed by an instrument that does not make any contact with the subject. In this article a review of respiration monitoring approaches (both contact and noncontact) is provided. Concerns related to the patient's recording comfort, recording hygiene, and the accuracy of respiration rate monitoring have resulted in the development of a number of noncontact respiration monitoring approaches. A description of thermal imaging based and vision based noncontact respiration monitoring approaches we are currently developing is provided. Pediatr. Pulmonol. 2011; 46:523–529. © 2011 Wiley‐Liss, Inc.
On the behaviour of nitrate esters in acid solution. III. Oxidation of ethanol by nitric acid in sulphuric acid
Authors: Camera E. , Modena G. , Zotti B.
Published: January 2011

The oxidation of ethanol as a model of the alcohols produced in the hydrolysis of nitrate esters, by nitric acid in aqueous sulphuric acid solutions has been studied with the aim to obtain information on the decomposition reaction of “spent acids”. The results show, in agreement with previous suggestions from this laboratory, that ethanol is firstly oxidized to acetaldehyde via a reaction initiated by nitric acid but carried on by NO2 radical. The latter is formed by the interaction of nitric and nitrous acids. The acetaldehyde is then oxidized by two independent paths leading one to acetic acid and the other to oxalic acid and eventually to CO2. The relevance of these findings on the understanding and on the control of „spent acids”︁ is briefly discussed.
Sur les lois de propagation des ondes de combustion dans les solides (Réactions pyrotechniques
Authors: Bernard M. L.
Published: January 2011

On the Propagation Laws of Combustion Waves in Solids (Pyrotechnic Reactions)

The existing theoretical models accounting for the rate of propagation of combustion waves in solids involve conductive heat transfer. We show that in metal/oxidizer systems, this rate can be recalculated with satisfying accuracy from the thermal diffusivity. The size of the particles strongly effects this property. We suggest to represent the variability of pyrotechnical compositions by a “characteristic curve” which represents the variation of slowness of the combustion wave (v−1) as a function of the reciprocal of heat of reaction (|ΔH|−1).
Structure and properties of the potassium hydroxide‐dinitrobenzofuroxan adduct (KDNBF) and related explosive salts
Authors: Spear R. J. , Norris W. P.
Published: January 2011

The structure of KDNBF was previously shown to be as in formula (2), Mn+ = K+, a Meisenheimer complex of 4,6‐dinitrobenzofurazan‐1‐oxide and potassium hydroxide(3,4,5). The corresponding sodium, silver and barium salts are shown to have identical molecular structure to KDNBF on the basis of IR and NMR spectral data. Explosive properties of the four salts were determined. The barium salt is substantially less sensitive to thermal, electrostatic and mechanical stimulae relative to the other three salts.
Cook‐off studies of propellants and explosives
Authors: Erneux T. , Arijs J. , Meŷsmans R.
Published: January 2011

A theoretical and an experimental study of the cook‐off problem is proposed. The critical temperature for thermal explosion is analyzed as a function of the initial mass of propellant. A good agreement is found between theory and experiments.
Mechanical stability of multidomain proteins and novel mechanical clamps
Authors: Sikora Mateusz , Cieplak Marek
Published: February 2011

We estimate the size of mechanostability for 318 multidomain proteins which are single‐chain and contain up to 1021 amino acids. We predict existence of novel types of mechanical clamps in which interdomain contacts play an essential role. Mechanical clamps are structural regions which are the primary source of a protein's resistance to pulling. Among these clamps there is one that opposes tensile stress due to two domains swinging apart. This movement strains and then ruptures the contacts that hold the two domains together. Another clamp also involves tensile stress but it originates from an immobilization of a structural region by a surrounding knot‐loop (without involving any disulfide bonds). Still another mechanism involves shear between helical regions belonging to two domains. We also consider the amyloid‐prone cystatin C which provides an example of a two‐chain 3D domain‐swapped protein. We predict that this protein should withstand remarkably large stress, perhaps of order 800 pN, when inducing a shearing strain. The survey is generated through molecular dynamics simulations performed within a structure‐based coarse grained model. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Colloidal Cu2ZnSnS4 nanocrystals generated by a facile route using ethylxanthate molecular precursors
Authors: Liu Yufeng , Ge Meiying , Yue Yang , Sun Yan , Wu Yizheng , Chen Xin , Dai Ning
Published: February 2011

We have demonstrated a flexible method for preparing Cu2ZnSnS4 (CZTS) nanocrystals by use of zinc ethylxanthate (Zn(ex)2) and copper ethylxanthate (Cu(ex)2). TEM, SEM, XRD, UV–vis, EDS, XPS and TG‐DTA indicate that the CZTS nanocrystals have been successfully synthesized. As air‐stable molecular precursors, Zn(ex)2 and Cu(ex)2 can optimize the synthesis of quaternary CZTS nanocrystals because Cu(ex)2 and Zn(ex)2 facilitate the formation of homogeneous precursor solutions including all precursors and then for the flexible production of CZTS nanocrystals in homogeneous reaction solutions. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydrogen isotope correction for laser instrument measurement bias at low water vapor concentration using conventional isotope analyses: application to measurements from Mauna Loa Observatory, Hawaii
Authors: Johnson L. R. , Sharp Z. D. , Galewsky J. , Strong M. , Van Pelt A. D. , Dong F. , Noone D.
Published: February 2011

The hydrogen and oxygen isotope ratios of water vapor can be measured with commercially available laser spectroscopy analyzers in real time. Operation of the laser systems in relatively dry air is difficult because measurements are non‐linear as a function of humidity at low water concentrations. Here we use field‐based sampling coupled with traditional mass spectrometry techniques for assessing linearity and calibrating laser spectroscopy systems at low water vapor concentrations. Air samples are collected in an evacuated 2 L glass flask and the water is separated from the non‐condensable gases cryogenically. Approximately 2 µL of water are reduced to H2 gas and measured on an isotope ratio mass spectrometer.

In a field experiment at the Mauna Loa Observatory (MLO), we ran Picarro and Los Gatos Research (LGR) laser analyzers for a period of 25 days in addition to periodic sample collection in evacuated flasks. When the two laser systems are corrected to the flask data, they are strongly coincident over the entire 25 days. The δ2H values were found to change by over 200‰ over 2.5 min as the boundary layer elevation changed relative to MLO. The δ2H values ranged from −106 to −332‰, and the δ18O values (uncorrected) ranged from −12 to −50‰. Raw data from laser analyzers in environments with low water vapor concentrations can be normalized to the international V‐SMOW scale by calibration to the flask data measured conventionally. Bias correction is especially critical for the accurate determination of deuterium excess in dry air. Copyright © 2011 John Wiley & Sons, Ltd.
Study of the desorption/ionization mechanism in electrospray droplet impact secondary ion mass spectrometry
Authors: Asakawa Daiki , Hiraoka Kenzo
Published: February 2011

Electrospray droplet impact (EDI) secondary ion mass spectrometry (SIMS) is a desorption/ionization technique for mass spectrometry in which highly charged water clusters produced from an atmospheric‐pressure electrospray are accelerated in vacuum by several kV and impact on the sample deposited on the metal substrate. The abundances of the secondary ions for C60 and amino acids are measured as a function of the acceleration voltage of the primary charged water droplets. Two desorption/ionization mechanisms are suggested in the EDI ionization processes: low‐energy and high‐energy regimes. In the low‐energy regime, the excess charges in the primary droplets play a role in the formation of secondary ions. In the high‐energy regime, samples are ionized by the supersonic collision of the primary droplets with the sample. The yield of secondary ions increases by about three orders of magnitude with increase in the acceleration voltage of the primary droplets from 1.75 kV to 10 kV. Copyright © 2011 John Wiley & Sons, Ltd.
δ15N natural abundance in permafrost soil indicates impact of fire on nitrogen cycle
Authors: Conen Franz , Yakutin Mikhail V. , Puchnin Alexander N. , Leifeld Jens , Alewell Christine
Published: February 2011

The impact of fire on the nitrogen (N) cycle of natural ecosystems is arguable. Here we report and interpret an observation from boreal ecosystems in the Lena River basin, Sakha Republic (Yakutia), Russian Federation. Different types of permafrost soil (0–30 cm depth) were sampled along transects (60–150 m length) from the forest edge towards the centre of four separate thermokarst depressions under grassland. The average values of δ15N were remarkably similar within three transects, but differed systematically between them. Three findings point towards fire being the cause of the observed pattern. First, the spatial extent of systematic differences in soil δ15N coincides with the extent of typical fire scars in the region. Second, soil enrichment in 15N is larger in the proximity of settlements, where fire is generally more frequent than in more remote places. Third, there is a significant positive correlation between δ15N values and the ratio of black C to total N. These findings point towards fire having a marked impact on soil δ15N and, accordingly, on the N cycle of this cold and dry ecosystem. Copyright © 2011 John Wiley & Sons, Ltd.
Robust ℋ︁∞ sliding mode control for nonlinear stochastic systems with multiple data packet losses
Authors: Ma Lifeng , Wang Zidong , Bo Yuming , Guo Zhi
Published: February 2011

In this paper, an ℋ︁∞ sliding mode control (SMC) problem is studied for a class of discrete‐time nonlinear stochastic systems with multiple data packet losses. The phenomenon of data packet losses, which is assumed to occur in a random way, is taken into consideration in the process of data transmission through both the state‐feedback loop and the measurement output. The probability for the data packet loss for each individual state variable is governed by a corresponding individual random variable satisfying a certain probabilistic distribution over the interval [0 1]. The discrete‐time system considered is also subject to norm‐bounded parameter uncertainties and external nonlinear disturbances, which enter the system state equation in both matched and unmatched ways. A novel stochastic discrete‐time switching function is proposed to facilitate the sliding mode controller design. Sufficient conditions are derived by means of the linear matrix inequality (LMI) approach. It is shown that the system dynamics in the specified sliding surface is exponentially stable in the mean square with a prescribed ℋ︁∞ noise attenuation level if an LMI with an equality constraint is feasible. A discrete‐time SMC controller is designed capable of guaranteeing the discrete‐time sliding mode reaching condition of the specified sliding surface with probability 1. Finally, a simulation example is given to show the effectiveness of the proposed method. Copyright © 2011 John Wiley & Sons, Ltd.
Cryptanalysis of some conference schemes for mobile communications
Authors: He Daojing , Chen Chun , Ma Maode , Bu Jiajun
Published: January 2011

To allow many users to hold a secure teleconference in mobile networks, a secure conference scheme with dynamic participation is necessary. However, designing a secure and efficient conference scheme is a difficult task because wireless networks are susceptible to attacks and wireless devices have limited resources. Recently, a lightweight and secure conference scheme has been suggested. Later, it has been found that this solution has security weaknesses and a modified version to overcome them has been presented. Compared with other conference schemes, these two schemes have many advantages. In this short paper, security study of these conference schemes in mobile networks has been performed with the following findings: (1) both the original scheme and the modified version are still vulnerable to our proposed impersonation attack; (2) they lack a mechanism to confirm the delivery of relevant messages, leading to protocol disruption. Therefore, these two schemes cannot be deployed for the real world applications without further development. Then, some efficient countermeasures are given for enhancing the security of both schemes. Further, the security properties of the improved protocol are formally validated by a model checking tool called AVISPA. Finally, several basic principles are suggested for the design of a secure conference scheme. Copyright © 2011 John Wiley & Sons, Ltd.
A self‐determination theory approach to understanding stress incursion and responses
Authors: Weinstein Netta , Ryan Richard M.
Published: January 2011

Given the high costs of stress for both mental and physical health, understanding of how stress is incurred and how it is coped with has both theoretical and clinical significance. Self‐determination theory (SDT), a broad framework for understanding motivation and personality, speaks to many issues concerning stress‐related phenomena. Research based on SDT suggests that both less stress incursion and better coping with demanding events are associated with greater autonomous functioning, higher mindfulness, more interest‐taking in internal events, and lifestyles focused on pursuing intrinsic over extrinsic goals, among other factors. These topics are discussed within the growing body of empirical research stemming from SDT and linkages are drawn with the larger literature on stress and coping. Copyright © 2011 John Wiley & Sons, Ltd.
On developing the microelectronics industry: A systems approach
Authors: Kawamura Kazuhiko , Silva Wainer Da Silveira E
Published: February 2011

This article presents a systems approach to microelectronics industry development. Rapid technological advances and price reductions in the microelectronics industry are changing everything from offices to factories. Many countries, including some developing countries like Brazil, are already aware of the importance of microelectronics technology and are developing strategies to compete in the world market. Developing a microelectronics industry is a complex process, technology constituting only one dimension. This paper uses the systems approach as an overall framework, and systematically develops a model for the microelectronics industry. The model then is applied to Brazil to illustrate how it can help policy makers develop better strategies for microelectronics industry development.
Current status of hospital management information systems
Authors: Hoye R. E. , Bryant D. D.
Published: February 2011

Advanced information systems are becoming a critical factor for hospitals to meet internal needs and external demands. This article reviews the current approaches for usage of hospital information systems, and presents the results of a 1983 survey which examines the actual state of use in an urban area. Data show that most of the hospitals have a management information system with a few planning management science and decision support capability. However, there seems to be a lag between examples in the literature and common practice.
Recent advances in multivariable system modeling and identification algorithms and their applications
Authors: El‐Sherief H.
Published: February 2011

Due to the recent advances and diversity of the subject of modeling and identification of multivariable systems and its important applications in many different traditional and new areas, a need arises for a unification of the existing literature on this subject. In this paper, most of the algorithms which have been proposed for identifying linear discrete‐time multivariable systems from input‐output data will be studied and classified according to the model used. Also, different types of applications and related topics to the subject of multivariable system identification and the features of some identification algorithms when implemented on dedicated computers with limited word length will be discussed.
Methodology in the large: Modeling all there is
Authors: Gaines Brian R.
Published: February 2011

The human mind has been inventive of a multitude of methodologies to explain observed phenomena, predict possible worlds, determine which ones should be made real and bring this about. In recent years the computer has enhanced our capability to project the detail of possible worlds and widen our vision of the consequences of our actions. We bring together the physical and human variables, political and economic policies and constraints of resources and expect increasing model realism. With advances in computer technology we have begun to see the possibility of large‐scale methodologies that eventually cope with all there is. This paper is concerned with placing our endeavours for model realism in the socioeconomic sphere within the much broader context of humankind's overall endeavours for model realism. It expresses the main philosophical problems underlying our situation in a parable, and then goes on to sketch some of the solutions proposed for them in the past. It concludes with a model for the role of the computer as a vehicle to explore Popper's World 3, and the use of his notion of three worlds to express the different styles and motivations of schools of modeling and concepts of realism.
Bureaucracy as organizational pathology
Authors: Acar William , Aupperle Kenneth E.
Published: February 2011

This paper investigates the strengths and weaknesses that bureaucracies derive from their structural rigidity. The first section delineates the historic mission of bureaucracy and its perceived gradual perversion. A second section examines the mechanism through which bureaucracy degenerates from an organizational optimization to an organizational pathology. The viewpoint espoused here reflects the systems approach, particularly such authors as Ackoff, Emery and Trist, and the connection they envision between function, adaptation and learning. It is basically argued that the modern phenomenon of overbureaucratization takes its roots in a deterministic view of causality and a rigid quest for optimality. It is also argued in a final section that bureaucracy has become a systemic phenomenon with a potential for exporting pathological behavior beyond strict organizational boundaries. The discussion implicitly illustrates the advantage of adaptive mechanisms of management and control over non‐adaptive mechanisms which are initially set to produce optimality.
The emergence of two‐dimensional science in the information society
Authors: Klir George J.
Published: February 2011

The paper overviews characteristics of systems science and three basic types of societies—the pre‐industrial society, industrial society and information (or post‐industrial) society. The meanings of systems knowledge, methodology and metamethodology are discussed. It is argued that systems science is a product of the information society and that it represents a new dimension in science, complementary to traditional science.
Editorial: Software survey section
Authors: Warfield John N. , Hall Thompson
Published: February 2011

The introduction of a new Software Survey Section to SYSTEMS RESEARCH is to encourage the open exchange of information on software programs relevant to our professional field. With the rapid penetration of computers into academic and industrial institutions has come a parallel increase in the number of scientists and researchers designing their own software. The existence of much of this software remains unknown to even those of us who could most benefit from its use. We believe that it is of vital importance to our readers that such information be made available. We believe also that a professional journal is the best place to share such information. Your contribution would be most welcome.
Dynamics in hierarchically organized systems: A general model applied to ecology, biology and economics
Authors: Auger Pierre
Published: February 2011

Physical and biological systems are composed with many levels of organization. To these different levels of organization are associated different levels of description, i.e. large classes of models relative to each of these levels. For instance, in ecology, roughly one distinguishes three levels of organization, the individual level, the population level and the ecosystem level, and consequently three large classes of models may be found, individual strategy models, population dynamical models (like the Leslie model) and ecosystem dynamical models (like the Lotka‐Volterra model). In this work, we present general methods to jump from one level to the next. For a two level system, one obtains two weakly coupled sets of equations (each one being relative to each level). The coupling terms allow one to study the interactions between the levels. This general method is then applied to ecology (coupled individual and population levels), to molecular and cellular biology (coupled chemical and cellular levels), and to economics (coupled sectorial and regional levels). One of our particular interests is to be able to obtain experimental verifications of the inter‐level coupling effects, which means simultaneous using of experimental data relative to both levels for the same system.
Strategic planning for research and management of the albacore tuna fishery: Correction
Authors: Mackett David J.
Published: February 2011

The following figure (p. 53) was omitted from “Strategic Planning for Research and Management of the Albacore Tuna Fishery” by D. J. Mackett, published in Systems Research Vol. 2, No. 3, pp. 201–210. This figure, Fig. 4, is a graphic display of the final results of the design process described in the article.
System theory as frame of reference in natural language processing
Authors: Vaccari E. , Delaney W.
Published: February 2011

We describe the overall philosophy of a computational approach to natural language processing entirely developed in a System Theory Paradigm. A metalanguage to represent world knowledge and theoretical system knowledge is described and criteria for a semantic parsing based on a systems approach are outlined. The approach is applicable to a variety of natural language, which is restricted but not limited to one discourse domain.
An options‐choice methodology for technological projects in developing countries
Authors: Al‐Khayat Faleh H. M. , Edwards John S.
Published: February 2011

Making decisions about large technological projects is never straightforward, because of their sheer complexity. However, when carried out in an environment in which the major considerations are financial, the task is simplified by the dominance of quantifiable criteria. In developing countries, on the other hand, the importance of such large technological projects to the country's overall development in social and technological, as well as economic, terms requires an evaluation process based on multiple criteria. The resolution of conflicts between these criteria is further complicated by the multiple agencies which are involved in a typical project in a centrally‐planned developing country. A structured systems approach to the decision‐making process is therefore clearly necessary. This paper sets out a methodology for options choice in the context of a large technological project in a developing country which is undergoing rapid growth and relies on central planning and control.