bluuebunny/crossref_metadata_2025 huggingface dataset:
The Incidence of Adjacent Segment Disease Requiring Surgery After Anterior Cervical Diskectomy and Fusion: Estimation Using an 11-Year Comprehensive Nationwide Database in Taiwan
Authors: Wu Jau-Ching , Liu Laura , Huang Wen-Cheng , Chen Yu-Chun , Ko Chin-Chu , Wu Ching-Lan , Chen Tzeng-Ji , Cheng Henrich , Su Tung-Ping
Published: October 2011

Background:

The incidence of symptomatic adjacent segment disease (ASD) after anterior cervical diskectomy and fusion (ACDF) was reported as 2.9%/y in a previous cohort of 374 patients. Few other data corroborate the incidence and natural history of ASD.

Objective:

To calculate the incidence of ASD after ACDF that required secondary fusion surgery.

Methods:

The retrospective study used an 11-year nationwide database to analyze the incidences. All patients who underwent ACDF for cervical disk diseases were identified through diagnostic and procedure codes. Kaplan-Meier and Cox regression analyses were performed.

Results:

From 1997 to 2007, covering 241 800 725.8 person-years, 19 385 patients received ACDF and 568 had ≥ 2 ACDF operations. The incidence of secondary ACDF operations was 7.6 per 1000 person-years. At the end of the 10-year cohort, 94.4% of patients who had received 1 ACDF remained free from secondary ACDF. The average time interval between the first and second ACDF was 23.3 months. After adjustment for comorbidities and socioeconomic status, secondary ACDF operations were more likely performed on male patients (hazard ratio = 1.27; P = .008) 15 to 39 years of age (hazard ratio = 1.45; P = .009) and 40 to 59 years of age (hazard ratio = 1.41, P = .002, respectively).

Conclusion:

Repeat ACDF surgery for ASD cumulated steadily in an annual incidence of approximately 0.8%, much lower than the reported incidence of symptomatic ASD. However, at the end of this 10-year cohort, a considerable portion of patients (5.6%) received a second operation. Younger and male patients are more likely to receive such second operations.
Styloidogenic Jugular Venous Compression Syndrome: Diagnosis and Treatment: Case Report
Authors: Dashti Shervin R. , Nakaji Peter , Hu Yin C. , Frei Don F. , Abla Adib A. , Yao Tom , Fiorella David , Ogungbo B.
Published: October 2011

Background and Importance:

Intracranial venous hypertension is known to be associated with venous outflow obstruction. We discuss the diagnosis and treatment of mechanical venous outflow obstruction causing pseudotumor cerebri.

Clinical Presentation:

We report 2 patients presenting with central venous outflow obstruction secondary to osseous compression of the internal jugular veins at the craniocervical junction. The point of jugular compression was between the lateral tubercle of C1 and a prominent, posteriorly located styloid process. In both cases, catheter venography showed high-grade jugular stenosis at the level of C1 with an associated pressure gradient. The dominant jugular vein was decompressed after the styloid process was resected. Postoperative imaging confirmed resolution of the jugular stenosis and normalization of preoperative pressure gradients. In both cases, the symptoms of intracranial hypertension resolved.

Conclusion:

Intracranial venous hypertension may result from extrinsic osseous compression of the jugular veins at the skull base. Although rare, this phenomenon is important to recognize because primary stenting not only is ineffective but also may actually exacerbate the outflow obstruction. The osseous impingement of the dominant jugular vein can be relieved via a decompressive styloidectomy, and the clinical results can be excellent.
Gamma Knife Thalamotomy for Parkinson Disease and Essential Tremor: A Prospective Multicenter Study
Authors: Ohye Chihiro , Higuchi Yoshinori , Shibazaki Toru , Hashimoto Takao , Koyama Toru , Hirai Tatsuo , Matsuda Shinji , Serizawa Toru , Hori Tomokatsu , Hayashi Motohiro , Ochiai Taku , Samura Hirofumi , Yamashiro Katsumi
Published: October 2011

BACKGROUND:

No prospective study of gamma knife thalamotomy for intractable tremor has previously been reported.

Objective:

To clarify the safety and optimally effective conditions for performing unilateral gamma knife (GK) thalamotomy for tremors of Parkinson disease (PD) and essential tremor (ET), a systematic postirradiation 24-month follow-up study was conducted at 6 institutions. We present the results of this multicenter collaborative trial.

Methods:

In total, 72 patients (PD characterized by tremor, n = 59; ET, n = 13) were registered at 6 Japanese institutions. Following our selective thalamotomy procedure, the lateral part of the ventralis intermedius nucleus, 45% of the thalamic length from the anterior tip, was selected as the GK isocenter. A single 130-Gy shot was applied using a 4-mm collimator. Evaluation included neurological examination, magnetic resonance imaging and/or computerized tomography, the unified Parkinson's disease rating scale (UPDRS), electromyography, medication change, and video observations.

Results:

Final clinical effects were favorable. Of 53 patients who completed 24 months of follow-up, 43 were evaluated as having excellent or good results (81.1%). UPDRS scores showed tremor improvement (parts II and III). Thalamic lesion size fluctuated but converged to either an almost spherical shape (65.6%), a sphere with streaking (23.4%), or an extended high-signal zone (10.9%). No permanent clinical complications were observed.

Conclusion:

GK thalamotomy is an alternative treatment for intractable tremors of PD as well as for ET. Less invasive intervention may be beneficial to patients.
Surgical vs Nonoperative Treatment of Hadley Type IIA Odontoid Fractures
Authors: Aldrian Silke , Erhart Jochen , Schuster Rupert , Wernhart Simon , Domaszewski Florian , Ostermann Roman , Widhalm Harald , Platzer Patrick
Published: October 2011

Background:

Type II odontoid fractures with additional chip fragments are rare in clinical practice, accounting for < 10% of all odontoid fractures. Hadley et al were the first to describe these fractures as an individual subtype (IIA).

Objective:

To analyze the outcome of patients after surgical or nonoperative treatment of Hadley type IIA odontoid fractures.

Methods:

We analyzed the records of 46 patients at an average of 64 years of age at the time of injury. Twenty-five patients underwent surgical stabilization by anterior screw fixation and were entered into study group A; 21 patients were treated non-operatively by halo vest immobilization and included in study group B.

Results:

Thirty-seven patients (84%) returned to their preinjury activity level and were satisfied with their treatment. Using the Cervical Spine Outcomes Questionnaire to quantify the clinical outcome, we had an overall outcome score of 21.8. We did not find a significant difference in the overall clinical outcome between study groups. Bony fusion was achieved in 35 patients (80%). We had a nonunion rate of 13% after anterior screw fixation and a significantly higher rate of 30% after halo vest immobilization. Failure of reduction or fixation occurred in 12 patients (27%), with a significantly higher failure rate after halo vest immobilization.

Conclusion:

Hadley type IIA odontoid fractures are inherently unstable and impede proper realignment. These fractures have a significantly increased risk for secondary loss of reduction and bony nonunion, particularly after nonoperative management. Early surgery should be considered to avoid further complications.
Back Pain: A Real Target for Spinal Cord Stimulation?
Authors: Rigoard Philippe , Delmotte Alexandre , D'Houtaud Samuel , Misbert Lorraine , Diallo Bakari , Roy-Moreau Aline , Durand Sylvain , Royoux Solène , Giot Jean-Philippe , Bataille Benoit
Published: October 2011

Background:

Failed back surgery syndrome represents one of the most frequent etiologies of chronic back pain and is a major public health issue. Neurostimulation has currently not been validated in the treatment of back pain because of technological limitations in implantable spinal cord stimulation (SCS) systems. New-generation leads using several columns of stimulation can generate longitudinal and/or transverse stimulation fields into the spinal cord.

Objective:

To investigate, through extensive stimulation testing, the capacity of multicolumn tripolar leads to achieve back territory paresthesia coverage in refractory failed back surgery syndrome patients.

Methods:

Eleven patients implanted with a 16-contact spinal cord stimulation lead (Specify 5-6-5, Medtronic Inc) were assessed with a systematic exploration of 43 selected stimulation configurations to generate bilateral back paresthesia in addition to leg territory coverage.

Results:

The tripolar lead successfully generated paresthesia in both bilateral back and leg territories in 9 patients (81.8%). Success rates of multicolumn stimulation patterns were significantly higher than for longitudinal configurations for lombodorsal paresthesia coverage. Six months after implantation, significant pain relief was obtained compared with preoperative evaluation for global pain (Visual Analog Scale, 2.25 vs 8.2 preoperatively; P < .05), leg pain (Visual Analog Scale, 0.5 vs 7.6 preoperatively; P < .05), and back pain (Visual Analog Scale, 1.5 vs 7.8 preoperatively; P < .05).

Conclusion:

These results suggest that multicolumn leads can reliably generate back pain coverage and favor pain relief outcomes. This may lead physicians to reconsider new indications for spinal cord stimulation. Expanding neurostimulation perspectives to intractable back pain syndromes could become realistic in the near future.
Economic Shocks and Civil Conflict: A Comment
Authors: Ciccone Antonio
Published: October 2011

Edward Miguel, Shanker Satyanath, and Ernest Sergenti (2004), henceforth MSS, argue that lower rainfall levels and negative rainfall shocks increase conflict risk in sub-Saharan Africa. This conclusion rests on their finding of a negative correlation between conflict in t and rainfall growth between t — 1 and t — 2. I show that this finding is driven by a (counterintuitive) positive correlation between conflict in t and rainfall levels in t — 2. If lower rainfall levels or negative rainfall shocks increased conflict, MSS's finding should have been due to a negative correlation between conflict in t and rainfall levels in t – 1. In the latest data, conflict is unrelated to rainfall. (JEL D74, E32, O11, O17, O47)
Re-examining Economic Shocks and Civil Conflict
Authors: Miguel Edward , Satyanath Shanker
Published: October 2011

Miguel, Satyanath, and Ernest Sergenti (2004), henceforth MSS, show that economic growth is negatively related to civil conflict in Africa, using annual rainfall variation as an IV for growth. Antonio Ciccone (2011) argues that thanks to rainfall's mean-reverting nature, rainfall levels are preferable to annual changes. We make three points. First, MSS's findings hold using rainfall levels as instruments. Second, Ciccone (2011) does not provide theoretical justification for preferring rainfall levels. Third, the first-stage relationship between rainfall and growth is weaker after 2000, suggesting that alternative instruments are needed when studying recent conflicts. We highlight the accumulating microeconomic evidence that adverse economic shocks lead to political violence. (JEL D74, E32, O11, O17, O47)
Evaluation of apparent diffusion coefficient mappings in amnestic mild cognitive impairment using an image analysis software brain search
Authors: Zhang Bing , Zhang Jian-ge , Zhao Hui , Zhang Xin , Li Ming , Qian Lai , Wang Kun , Tian Chuan-shuai , Guo Wan-hua , Cao Qiu-yun , Zhou Zheng-yang , Yu Haiping , Li Chen , Xu Jun , Cao Wangsen , Zhu Bin , Xu Yun
Published: October 2011

Background

The apparent diffusion coefficient (ADC) from diffusion-weighted imaging (DWI) can quantify alterations in water diffusivity resulting from microscopic structural changes from amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD).

Purpose

To investigate the ADC value for aMCI and AD using Brain Search (BS) software based on anatomical volumes of interest (AVOI).

Material and Methods

In total, 174 aged people were screened, and 25 patients with AD, 26 patients with aMCI, and 18 normal controls (NCs) were recruited. DWI was performed at 1.5 T with a fluid-attenuated inversion recovery (FLAIR), and the independent ADC mapping was generated after imaging acquisition. Ninety regional parcellations were adopted in a Brain Search (BS) based on the automated anatomic labeling atlas. The gray scale intensities (water diffusivity) from the collected ADC mappings were analyzed with BS. The mean value of each anatomical brain region was compared among aMCI, AD, and NC. The statistically significant ( P < 0.05) group differences are displayed in color.

Results

During the pathological process of AD, the changes of water diffusivity appeared first in the left hippocampus, then gradually progressed to the bilateral sides and eventually displayed right lateralization. The ADC values from aMCI were obviously elevated compared to the values from the NC group in the left limbic cortex. Between the AD and NC groups, the significantly different brain areas included the bilateral hippocampus, the Cingulum_Mid, the ParaHippocampal_R, and the Temporal and Frontal lobes. There was a negative correlation between the ADC values and the scores from MMSE, MoCA, the Digit test, Raven's IQ, and WAIS IQ. Additionally, the ADC values were positively correlated with the scores from CDR, ADL, and ADAS-Cog.

Conclusion

The water diffusivity for aMCI and AD displays asymmetric anatomical lateralization. The water diffusivity alterations can be analyzed and visualized with our newly designed analytic imaging software, BS, which can be used as a good reference for examining and diagnosing aMCI and AD patients.
In-vivo near-infrared optical imaging of growing osteosarcoma cell lesions xenografted in mice: dual-channel quantitative evaluation of volume and mineralization
Authors: Nakayama Hitoshi , Kawase Tomoyuki , Okuda Kazuhiro , Wolff Larry F , Yoshie Hiromasa
Published: October 2011

Background

In a previous study using a rodent osteosarcoma-grafted rat model, in which cell-dependent mineralization was previously demonstrated to proportionally increase with growth, we performed a quantitative analysis of mineral deposit formation using 99mTc-HMDP and found some weaknesses, such as longer acquisition time and narrower dynamic ranges (i.e. images easily saturated). The recently developed near-infrared (NIR) optical imaging technique is expected to non-invasively evaluate changes in living small animals in a quantitative manner.

Purpose

To test the feasibility of NIR imaging with a dual-channel system as a better alternative for bone scintigraphy by quantitatively evaluating mineralization along with the growth of osteosarcoma lesions in a mouse-xenograft model.

Material and Methods

The gross volume and mineralization of osteosarcoma lesions were evaluated in living mice simultaneously with dual-channels by NIR dye-labeled probes, 2-deoxyglucose (DG) and pamidronate (OS), respectively. To verify these quantitative data, retrieved osteosarcoma lesions were then subjected to ex-vivo imaging, weighing under wet conditions, microfocus-computed tomography (μCT) analysis, and histopathological examination.

Results

Because of less scattering and no anatomical overlapping, as generally shown, specific fluorescence signals targeted to the osteosarcoma lesions could be determined clearly by ex-vivo imaging. These data were well positively correlated with the in-vivo imaging data ( r > 0.8, P < 0.02). Other good to excellent correlations ( r > 0.8, P < 0.02) were observed between DG accumulation and tumor gross volume and between OS accumulation and mineralization volume.

Conclusion

This in-vivo NIR imaging technique using DG and OS is sensitive to the level to simultaneously detect and quantitatively evaluate the growth and mineralization occuring in this type of osteosarcoma lesions of living mice without either invasion or sacrifice. By possible mutual complementation, this dual imaging system might be useful for accurate diagnosis even in the presence of overlapping tissues.
Accuracy of CT-guided biopsies in 158 patients with thoracic spinal lesions
Authors: Hao DJ , Sun HH , He BR , Liu TJ , Jiang YH , Zhao QP
Published: October 2011

Background

Inconsistent accuracies of CT-guided thoracic spinal biopsies have been reported in previous studies.

Purpose

To determine the accuracy of CT-guided thoracic spinal biopsy, to compare the results with those previously reported, and to determine if there are any factors that influence the accuracy of CT-guided thoracic spinal biopsy.

Material and Methods

In total, 158 consecutive CT-guided percutaneous thoracic spine procedures (performed at the Department of Spinal Surgery, Xi‘an Red Cross Hospital between April 2000 and July 2010) were reviewed. The 158 lesions were categorized by location and radiographic features. Pathological and clinical follow-up were used to determine accuracy.

Results

The diagnostic accuracy of CT-guided thoracic spinal biopsy was 90.5% overall. Biopsy of metastatic bone disease (98.2%) was significantly more accurate than biopsies of primary tumors (80.9%) and of hematological malignancies (47.0%) ( P < 0.05 and P < 0.005, respectively). The diagnostic accuracy of CT-guided thoracic spinal biopsy was significantly higher for the lower thoracic spine (97.6%) than for the middle (90.0%) or upper thoracic spine (80.4%) ( P < 0.05 and P < 0.025, respectively). The diagnostic accuracy was significantly higher for lytic lesions (96.4%) than for sclerotic lesions (81.3%) ( P < 0.010). The accuracy of biopsies performed using the transpedicular approach (91.0%) was not significantly different from that of biopsies performed using posterolateral approaches (91.5%) (0.25 < P < 0.5).

Conclusion

Percutaneous CT-guided thoracic spinal biopsy is a viable alternative to open surgical biopsy. The diagnostic accuracy was not affected by any of the variables except for lesion level, histology, and radiographic features.
Prevalence and characteristics of the metabolic syndrome in 2479 hypopituitary patients with adult-onset GH deficiency before GH replacement: a KIMS analysis
Authors: Verhelst Johan , Mattsson Anders F , Luger Anton , Thunander Maria , Góth Miklós I , Kołtowska-Häggström Maria , Abs Roger
Published: October 2011

Objective

An increased risk of cardiovascular morbidity and mortality in adult GH deficiency (GHD) may be related to hypopituitarism but also to the presence of the metabolic syndrome (MetS). Our objective was to investigate the characteristics and prevalence of MetS as well as its comorbidities in adult GHD.

Design

In KIMS (Pfizer International Metabolic Database) 2479 patients with severe adult-onset GHD, naïve to GH replacement, with complete information on all MetS components were found. MetS was defined according to the National Cholesterol Education Program's Adult Treatment Panel III (NCEP) and the International Diabetes Foundation (IDF).

Methods

The prevalence of MetS was calculated and compared with previously published data from the normal population. Associations were assessed between background variables, baseline variables, comorbidities, and MetS.

Results

MetS was present in 43.1% (NCEP) and in 49.1% (IDF) of patients, clearly higher than data from the normal population (20–30%). MetS prevalence was related to age, GHD duration, and body mass index (BMI), but not to GHD severity, extent of hypopituitarism, or etiology of pituitary disease. Adjusted for age, gender, and BMI, patients with MetS had a higher prevalence ratio for diabetes mellitus: 4.65 (95% confidence interval (CI): 3.29–6.58), for cardiovascular morbidity: 1.91 (95% CI: 1.33–2.75), and for cerebrovascular morbidity: 1.77 (95% CI: 1.09–2.87) than patients without MetS.

Conclusions

MetS is highly prevalent in GHD and is associated with a higher prevalence ratio for comorbidities. The presence of MetS in GHD may therefore contribute to the increased risk of cardiovascular morbidity and mortality found in these patients.
One-dimensional nanostructured materials for solar energy harvesting
Authors: Han Ning , Wang Fengyun , Ho Johnny C.
Published: October 2011

As the energy demand is rapidly increasing worldwide compared with the supply, there is an urgent need to develop alternative energy-harvesting technologies to sustain the economic growth. Among them, solar energy is one of the most promising sources as it is clean, abundant and renewable. Due to the unique optical and electrical properties, one-dimensional (1D) nanostructured semiconductors are attractive materials for the construction of active energy-harvesting devices. In this review article, applications of 1D nanostructured materials – including photovoltaics, photoelectrochemical cells and solar hydrogen production – in solar energy harvesting are summarized. With the efficiency enhancement and cost reduction, 1D nanostructured solar energy harvesting devices are found to be promising to tackle the future energy issue.
Labor Market Effects of the Exxon Valdez Oil Spill
Authors: Hore John , Carrington William J.
Published: October 2011

We study the labor market effects of the 1989 Exxon Valdez Oil Spill in Prince William Sound, Alaska, which was the largest U.S. oceanic oil spill prior to the 2010 Gulf Oil Spill. We find that employment and average earnings increased in 1989 when the cleanup effort was largest and there appears to have been little, if any, adverse effect on average labor market opportunities in later years. Increased wages elicited increased labor supply in the form of both in-migration of workers and increased weekly hours. While the labor market effects of the spill were largely beneficial, there is some evidence that the effects upon self-employed fishing boat owners in the region may have been more heterogeneous, with some owners signing lucrative cleanup contracts with Exxon and its agents while others did not. The existence of these positive labor effects does not address the significant environmental, psychological and social costs imposed on the region and on the communities whose livelihood and organization were affected by the spill.
Nowhere to Run and Nowhere to Hide: The Relationship between Entrepreneurial Success and Feelings of Entrapment
Authors: Wood Matthew S. , Rowe Jonathan D.
Published: October 2011

One unintended consequence of entrepreneurial action may be that the entrepreneur becomes intertwined with the business. This phenomenon is called entrapment and we draw on Becker’s Side-Bet Theory to explore the relationship between entrepreneurial success, individual differences, and feelings of entrapment. The general logic is that as venture success increases entrepreneurs are better able to satisfy commitments and have a greater sense of alternatives that reduce feelings of entrapment. We surveyed 122 active entrepreneurs and found support for the venture success — feelings of entrapment relationship. We also found significant direct relationships between feelings of entrapment and attitude towards risk and fear of failure, however, these variables did not moderate the venture success — entrapment relationship. One implication of our findings is that entrepreneurs running marginally performing businesses are likely to experience greater feelings of entrapment.
Innovation: Meager Private Gains, Enormous Social Gains
Authors: Baumol William
Published: October 2011

There is strong evidence that invention is an activity that is very risky for the inventor and that those who participate in the invention process, taken as a group, obtain a minuscule share of the benefits. Nevertheless, the evidence also indicates that the social benefits of invention in recent centuries have been enormous. Yet, the relatively few examples of enormous payoffs to the inventors and their investors may serve, like the multimillion dollar prizes offered by some lotteries, to stimulate a level of inventive activity that may even be close to the social optimum.
The effects of proposed tax changes on poverty and vulnerable groups in Serbia
Authors: Matkovic Gordana , Mijatovic Bosko
Published: October 2011

This paper provides an empirical analysis of the potential effects of a
proposed tax reform in Serbia on poverty and vulnerable groups. The essence
of the proposal is transferring the tax burden from wages to personal
consumption, thus alleviating one production factor and therefore stimulating
economic growth. The analysis utilizes the tax-benefit microstimulation
model, based on the Household Budget Survey for 2009. Since the model does
not include the production sector, the estimated effects are direct,
income-based, without the potential economic growth. As expected, the total
personal consumption in Serbia would decrease (-3.4%), while poverty would
increase (from 6.9 to 7.4%). All of the potentially vulnerable groups would
be relatively equally affected. The conclusion is that it is questionable
whether it is prudent to implement a tax reform during times of crisis and
increased poverty that would probably result in negative short term social
outcomes and whose long term effects are still unclear.
Deprotonation of salicylic acid and 5-nitrosalicylic acid in aqueous solutions of ethanol
Authors: Faraji Mohammad , Farajtabar Ali , Gharib Farrokh , Ghasemnejad-Borsa Hassan
Published: October 2011

The protonation constant values of two hydroxybenzoic acids (salicylic and
5-nitrosalicylic acid) were studied in some water-ethanol solutions using
spectrophotometric and potentiometric methods at 25?C and in an ionic
strength of 0.1 M sodium perchlorate. The results indicated that the pKa
values increase with increasing proportion of ethanol in mixed solvent. The
dependence of the protonation constants on the variation of the solvent were
correlated by the dielectric constants of the media. Furthermore, for a
better understanding of the solvent influence, the obtained results were
explained in terms of the Kamlet-Taft parameters ? (hydrogen-bond donor
acidity), ?
Interdependence of fundamental and applied research in material science
Authors: Kosanovic D. , Maricic A. , Mitrovic N. , Ristic M.M.
Published: October 2011

Development of materials with desirable properties essentially depends on
realization of interdependence: natural science ? technical sciences. Taking
this into account, in order to develop of new advanced materials it is
essential to determine principles that characterize this interdependency.
Therefore, in this article the principles of fundamental research and the
importance of obtained results are considered and implemented in the field of
technical realizations.
Formation of mesostructure in WC-Co cemented carbides: A review
Authors: Lisovsky A.F.
Published: October 2011

The author considers potential lines in the formation of mesostructures in
cemented carbides, analyzes the existing technologies of the formation
thereof, describes physical and mechanical properties of cemented carbides
with mesostructure and shows the efficiency of such cemented carbides in
metal working and rock destruction tools.
Damage types of crossed helical gears with wheels from sintered steel
Authors: Miltenovic A. , Predki W.
Published: October 2011

Sintered steel appears to be a very effective material for wheels in crossed
helical gears. High demands are set on gears made from sintered steel
regarding wear, fretting, tooth fracture and pitting load capacity. This
report shows results of iron-based sintered material Fe1.5Cr0.2Mo in case of
crossed helical gears concerning wear resistance and other damage types under
different speed, torque and lubricants. As material variants, samples with
additional treatment, such as pyrohydrolysis, case hardening, shot peening,
sinter-hardening, and 2% copper addition are used.
Translation of microwave methodology to continuous flow for the efficient synthesis of diaryl ethers via a base-mediated SNAr reaction
Authors: Wiles Charlotte , Watts Paul
Published: October 2011

Whilst microwave heating has been widely demonstrated as a synthetically useful tool for rapid reaction screening, a microwave-absorbing solvent is often required in order to achieve efficient reactant heating. In comparison, microreactors can be readily heated and pressurised in order to “super-heat” the reaction mixture, meaning that microwave-transparent solvents can also be employed. To demonstrate the advantages associated with microreaction technology a series of SNAr reactions were performed under continuous flow by following previously developed microwave protocols as a starting point for the investigation. By this approach, an automated microreaction platform (Labtrix® S1) was employed for the continuous flow synthesis of diaryl ethers at 195 °C and 25 bar, affording a reduction in reaction time from tens of minutes to 60 s when compared with a stopped-flow microwave reactor.
MANAGING SERVICE RECOVERY PROCESSES: THE ROLE OF CUSTOMER'S AGE / VARTOTOJŲ AMŽIAUS ĮTAKA PASLAUGŲ VERTINIMUI
Authors: Cambra-Fierro Jesús , Berbel-Pineda Juan M. , Ruiz-Benítez Rocío , Vazquez-Carrasco Rosario
Published: October 2011

Research and practice show that effective management of service recovery processes boosts customer satisfaction. Under this assumption, the purpose of this paper is to analyze a set of factors which may determine satisfaction with recovery processes and loyalty. We also analyze the role of age as potential moderating. Segmenting customers' samples by age may potentially contribute to more effective service recovery process management. Older customers seem to be more loyal when dealing with service providers than younger customers, while younger customers are more demanding in terms of companies' efforts. Implications for both literature and practice are included at the front-end of the paper. Santrauka Tiek moksliniai tyrimai, tiek ir praktika rodo, kad grąžinimo procesų valdymo veiksmingumas skatina klientų pasitenkinimą. Remiantis šia prielaida, straipsnio tikslas yra išanalizuoti veiksnius, turinčius įtakos klientų pasitenkinimo lygiui ir lojalumui. Taip pat analizuojamas ir vartotojų amžiaus rodiklis, jo potencialo kaita. Atsižvelgiant į tai, klientai buvo sugrupuoti pagal amžių ir buvo analizuojama, kaip vieni ar kiti procesai juos veikia. Atliktas tyrimas parodė, kad vyresnio amžiaus klientai yra labiau ištikimi nei jaunesni, o jaunesni klientai yra reiklesni įmonių teikiamoms paslaugoms.
HOW ENTREPRENEURIAL CHARACTERISTICS INFLUENCE COMPANY CREATION: A CROSS-NATIONAL STUDY OF 22 COUNTRIESTESTED WITH PANEL DATA METHODOLOGY / VERSLUMO CHARAKTERISTIKŲ ĮTAKA ĮMONĖS KŪRIMUI: STUDIJOS, ATLIKTOS 22 VALSTYBĖSE, REZULTATŲ PRISTATYMAS
Authors: Álvarez-Herranz Agustín , Valencia-De-Lara Pilar , Martínez-Ruiz María Pilar
Published: October 2011

This study analyzes, from a multicountry perspective, the influence of the sociodemographic profiles of nascent and new entrepreneurs on their behavior. The panel data-based research approach combines temporal series and cross-sectional data to assess entrepreneurial activities across 22 countries with varying income levels. The results show that entrepreneurs' characteristics influence entrepreneurial behavior significantly and positively, in the following order: previous experience of the founder, age, and education. These findings suggest valid recommendations for stimulating entrepreneurship, both for enterprising business founders and for the institutions responsible for designing economic and regional development policies. Santrauka Straipsnyje pristatomų tyrimų rezultatai apima sociodemografinių veiksnių įtakos naujai kuriamam verslui ir jo aplinkai analizę. Tyrimas buvo atliktas 22 valstybėse. Jo rezultatai rodo, kad tam tikros individualios asmens verslumo savybės turi teigiamą įtaką paties verslo organizavimui, pavyzdžiui, ankstesnė verslininko patirtis, amžius ir išsilavinimas. Straipsnio autoriai pateikia rekomendacijas, susijusias su verslumo skatinimu, jos turės įtakos ne tik ekonominei, bet ir regioninei vystymosi politikai.
RAISING GAS-DYNAMIC STABILITY MARGIN OF AXIAL AND CENTRIFUGAL COMPRESSOR STAGES BY MEANS OF VANED DIFFUSER BOUNDARY LAYER CONTROL / DUJŲ DINAMINIO STABILUMO RIBOS AŠINIO IR IŠCENTRINIO KOMPRESORIAUS PAKOPOSE DIDINIMAS ATLIEKANT STABILIZUOTO DIFUZORIAUS PARIBIO SLUOKSNIO KONTROLĘ
Authors: Lastivka Ivan
Published: October 2011

Generalised research results that consider the upgradability of axial and centrifugal gas turbine engine compressors by means of gas-dynamic boundary layer control on bladed disks are demonstrated. Active and passive methods are used. Comparative analysis of the results has been carried out. The analysis is purposed to determine the influence of the flow circulation around the aerofoils on the performance of compressor single-row bladed disks with smooth blades and rough blades and under the condition that vortex generators are installed.

An increase in the efficiency of aviation gas-turbine engines and in their gas-dynamic stability margin support leads to the enhancement of the parameters and performance of compressors: increase in loading of aerodynamic bladed disks, improvement of their economical efficiency, improvement of margin of the continuous flow around the compressor grids, etc.

Airflow in the compressor grid is characterised by the flow region in the flow core and also by the flow regions in the wall boundary layers on the grid blades where shock waves, vortices, air swirls, and flow separation phenomena take place.

The principle objective of the work is to research the possibilities of influence on the parameters of the elements of compressors and overall performance of gas-turbine engines via the methods of active and passive flow regulation.

Active flow regulation is realised either by rendering the auxiliary gas mass to the blades boundary layer, or by suction (withdrawal) of the boundary layer (its part) from the surfaces of blades. Passive flow around regulation is characterised by influence on the boundary layer by means of energy redistribution in the flow itself.

Santrauka

Šiuo tyrimu siekiama nustatyti sparno profilio aptekejimo įtaką vienos eiles menčių kompresoriaus su lygiomis ir šiurkščiomis mentemis darbui, esant įdiegtiems sūkurio generatoriams. Pagrindinis darbo tikslas – ištirti kompresoriaus elementų ir bendro dujų turbininių variklių darbo įtaką parametrams, taikant pasyvų ir aktyvų srauto reguliavimo metodus. Padidinus dujų turbininių variklių našumą ir jų dujų dinamikos stabilumo ribas, pagereja kompresorių darbas ir parametrai: padideja aerodinaminių diskų su mentemis apkrova, jie tampa ekonomiškai našesni, padideja nepertraukiamo srauto riba aplink kompresoriaus plokšteles.
Immune Deficiency Could be An Early Risk Factor for Altered Insulin Sensitivity in Antiretroviral-Naive HIV-1-Infected Patients: The Anrs Copana Cohort
Authors: Boufassa Faroudy , Goujard Cécile , Viard Jean-Paul , Carlier Robert , Lefebvre Bénédicte , Yeni Patrick , Bouchaud Olivier , Capeau Jacqueline , Meyer Laurence , Vigouroux Corinne ,   for the ANRS COPANA Cohort Study Group
Published: October 2011

Background

The relationships between immunovirological status, inflammatory markers, insulin resistance and fat distribution have not been studied in recently diagnosed (<1 year) antiretroviral-naive HIV-1-infected patients.

Methods

We studied 214 antiretroviral-naive patients at enrolment in the metabolic substudy of the ANRS COPANA cohort. We measured clinical, immunovirological and inflammatory parameters, glucose/insulin during oral glucose tolerance test (OGTT), adipokines, subcutaneous and visceral fat surfaces (subcutaneous adipose tissue [SAT] and visceral adipose tissue [VAT], assessed by computed tomography) and the body fat distribution based on dual-energy X-ray absorptiometry (DEXA).

Results

Median age was 36 years; 28% of the patients were female and 35% of sub-Saharan origin; 20% had low CD4+ T-cell counts (≤200/mm3). Patients with low CD4+ T-cell counts were older and more frequently of sub-Saharan Africa origin, had lower body mass index (BMI) but no different SAT/VAT ratio and fat distribution than other patients. They also had lower total, low-density lipoprotein and high-density lipoprotein cholesterolaemia, higher triglyceridaemia and post-OGTT glycaemia, higher markers of insulin resistance (insulin during OGTT and homeostasis model assessment of insulin resistance) and of inflammation (high-sensitivity C-reactive protein, IL-6, tumour necrosis factor (TNF)-α, sTNFR1 and sTNFR2). After adjustment for age, sex, geographic origin, BMI and waist circumference, increased insulin resistance was not related to any inflammatory marker. In multivariate analysis, low CD4+ T-cell count was an independent risk factor for altered insulin sensitivity (β-coefficient for HOMA-IR: +0.90; P=0.001; CD4+ T-cell count >500/mm3 as the reference), in addition to older age (P: +0.26 for a 10-year increase; P=0.01) and higher BMI (P: +0.07 for a 1-kg/m2 increase; P=0.003).

Conclusions

In ART-naive patients, severe immune deficiency but not inflammation could be an early risk factor for altered insulin sensitivity.
Relative Impact of Ribavirin Monitoring and HIV Coinfection on Sustained Virological Response in Patients with Chronic Hepatitis C
Authors:   the RibAct group, Piedoux Sarah , Monnet Elisabeth , Piroth Lionel , Montange Damien , Royer Bernard , Thevenot Thierry , Kantelip Jean Pierre , Martino Vincent Di , Muret Patrice
Published: October 2011

Background

In chronic hepatitis C, higher ribavirin (RBV) concentrations are associated with sustained virological response (SVR); target concentration cutoffs have been proposed. As RBV displays interindividual variability, monitoring of RBV plasma levels appears relevant. The impact of RBV therapeutic drug monitoring (TDMRBV) on SVR has not been explored in current practice. Our study aimed to assess this impact.

Methods

Three patient groups were defined as RBV cutoffs achieved at week 12 (group A1), not achieved (group A2), and one without RBV concentration assessment (group B). A predictive model assessed the group impact on SVR in multivariate analysis, while adjusting for additional predictive factors. A specific evaluation of HIV–HCV-coinfected patients was performed.

Results

A total of 122 patients were included. In group A1 ( n=30, HIV-positive =18), SVR, relapse and non-response rates were 60%, 17% and 23%, respectively; in group A2 ( n=32, HIV-positive =18), 25%, 19% and 56%, respectively; and in group B ( n=60, HIV-positive =3), 52%, 33% and 15%, respectively ( P=0.0004). The patient group was an independent predictor of SVR ( P=0.01), along with baseline viral load and HCV genotype. HIV coinfection did not impede the SVR rate. The cutoffs were achieved in 62% and 28% ( P=0.008) of patients, when TDMRBV was performed or not, respectively.

Conclusions

The achievement of RBV cutoffs is a predictive factor of SVR independent of HIV coinfection. It makes it possible to reach high SVR rates, avoid relapse and obtain the same SVR rates in HIV–HCV-coinfected as in HCV-monoinfected patients. TDMRBV enables RBV concentration cutoffs to be reached more frequently and could thus be a useful tool to optimize hepatitis C treatment.
Pork consumption in Brazil: challenges and opportunities for the Brazilian pork production chain
Authors: de Barcellos Marcia Dutra , de Melo Saab Maria Stella , Pérez-Cueto Federico , Perin Marcelo Gattermann , Neves Marcos Fava , Verbeke Wim
Published: October 2011

In spite of being the world's most consumed meat, pork ranks only third in Brazil, with a consumption level much lower than that of poultry and beef. Although consumption of fresh pork meat has been increasing in recent years, 67.9% of the Brazilian pork consumption is based on processed pork products. Despite the chain's many technological improvements in recent years, producers and industry are not yet focused on innovation nor on informing and captivating the new millennium's consumer. Brazil is a country of continental dimensions and recent changes in the economic status of the population have created a favourable environment for the development of new pork products. This study investigates consumers' eating habits, preferences and satisfaction using data collected from a survey among 482 consumers as part of the Q-PorkChains project in Brazil. Results indicate that consumers prefer fresh (not frozen) products and the supermarket is their preferred distribution channel. Pork products are consumed mostly at home, with family, on any day of the week. Consumers are generally satisfied with the products available in the market, although health aspects, convenience and price could be improved. Overall, the interviewed pork consumers in Brazil signal opportunities for the pork chain in terms of innovation and new product development.
Biomarkers as management tools for industries in the pork production chain
Authors: Te Pas Marinus , Hoekman Arend , Smits Mari
Published: October 2011

In livestock production, traits such as meat quantity and quality are mainly determined by biological processes. Knowing the biological background of traits makes it possible to identify relevant processes, genes or molecules that may be used as indicators to rapidly and easily detect the status and phase of biological processes. Such indicators are called biomarkers. Thus biomarkers provide information about the status and phase of biological processes underlying particular traits. This information can be used to modulate these processes and thereby optimize the economic value of these traits. To produce products from livestock, pork industries are organized in a production chain – from the breeding industry to the retail industry. Industries in a chain interact with each other to optimize economic value. (Automated) detection of biomarkers could activate processes throughout the chain that can be robotized and computerized, thereby creating economic benefit for all participants in the chain. Biomarkers may be used on individual animals and on pooled samples representing a whole herd for herd management. Here we describe how biomarkers can be developed and how they may be used to enhance value for the pork production chain industries.
Indexing in Data Warehouses
Authors: Davis Karen C. , Gupta Ashima
Published: October 2011

Bitmap Indexes (BIs) allow fast access to individual attribute values that are needed to answer a query by storing a bit for each distinct value and tuple. A BI is defined for a single attribute and the encodings are based solely on data values; the Property Map (PMap) is a multidimensional indexing technique that precomputes attribute expressions for each tuple and stores the results as bit strings. In order to determine whether the PMap is competitive with BIs, we conduct a performance study of the PMap with the Range Encoded Bit Sliced Index (REBSI) using cost models to simulate storage and query processing costs for different kinds of query types. We identify parameters that have significant effect on index performance and determine situations in which either index is more suitable. These results could be useful for improving the performance of an analytical decision making system.
The Selection of the IT Platform
Authors: Shakir Maha , Viehland Dennis
Published: October 2011

The Health Board is one of the largest public health care providers in New Zealand (NZ). In early 1999, a supply chain optimization review recommended an enterprise system (ES) implementation to provide better control and reporting of organizational finances. The focus of this case is the IT platform decision made in conjunction with the ES implementation process. This decision was thoroughly considered by all Health Board stakeholders and the final choice was made in alignment with the Board’s strategic IT policy. Nevertheless, initial testing two months prior to go-live revealed major performance problems with the new system. The case documents the events that led up to the selection of the original IT platform and the challenges the project team faced in deciding what to do when the platform did not meet contractual specifications.
Incentives and Knowledge Mismatch
Authors: Banerjee P.
Published: October 2011

The case study describes process reengineering at a major public bank of India. Choice between strategy, structure, technology, process and personnel remained a key issue. Integration of disparate processes on information technology platform proved mixed success
The Managerial Challenges in the Transformation of the Danish Geodata Sector
Authors: Frokjaer Erik , Korsbaek Helge
Published: October 2011

This case summarizes the organizational transformations in the Danish mapping, charting and geodata sector from the mid-eighties to the mid- nineties. New products and possibilities raised by information technology were the driving motive behind the ambition to develop an integrated national geographical information system (GIS).
A Business Model Framework for Second Life
Authors: D’Andrea Alessia , Ferri Fernando , Grifoni Patrizia
Published: October 2011

This chapter provides a framework to analyse the marketing and promotion advantages of Virtual Communities. Virtual Communities offer companies the possibility to carry out a new products and services promotion and to develop trustful relationships with customers. The key element in the use of Virtual Communities for these purposes is the wide amount of customers that can be reached. Virtual Communities present the aptitude to generate social influence and knowledge sharing among customers. As a consequence, it brings out the increasing number of skills, competencies and “knowledge profiles” of each customer involved in the virtual environment. The framework is consequently applied to Second Life in order to analyse three different business strategies that companies usually implement by using this platform. The first strategy allows companies to perform the placement of their products/services in a dynamic form. The second strategy provides companies the possibility to have a better knowledge of customers’ needs in order to develop products and services that satisfy customer’s expectations. Finally, the third strategy allows companies to develop high brand awareness.
E-Novation in Large Corporations
Authors: Conlin Michael
Published: October 2011

This chapter explores the lessons learned by large corporations that have been pioneers of e-novation. These pioneers have much to teach us about the opportunities for competitive impact and business value. These are explored within the framework of Porter’s Five Forces model. The impact of e-novation on employees and, especially on the employee-employer relationship is explored to reveal possible insights. Although a significant portion of these pioneers are in the high tech sector, many of the insights are broadly applicable to all sectors of the economy. A case is made that e-novation is well on its way to broad adoption in the business community. Recommendations are offered for those wishing to take up the challenge of e-novation.