bluuebunny/crossref_metadata_2025 huggingface dataset:
Essential role of paternal chromatin in the regulation of transcriptional activity during mouse preimplantation development
Authors: Bui Hong-Thuy , Wakayama Sayaka , Mizutani Eiji , Park Keun-Kyu , Kim Jin-Hoi , Van Thuan Nguyen , Wakayama Teruhiko
Published: October 2010

Several lines of evidence indicate that the formation of a transcriptionally repressive state during the two-cell stage in the preimplantation mouse embryo is superimposed on the activation of the embryonic genome. However, it is difficult to determine the profile of newly synthesized (nascent) RNA during this phase because large amounts of maternal RNA accumulate in maturing oocytes to support early development. Using 5-bromouridine-5′-triphosphate labeling of RNA, we have verified that nascent RNA synthesis was repressed between the two-cell and four-cell transition in normally fertilized but not in parthenogenetic embryos. Moreover, this repression was contributed by sperm (male) chromatin, which we confirmed by studying androgenetic embryos. The source of factors responsible for repressing nascent RNA production was investigated using different stages of sperm development. Fertilization with immature round spermatids resulted in a lower level of transcriptional activity than with ICSI at the two-cell stage, and this was consistent with further repression at the four-cell stage in the ICSI group. Finally, study on DNA replication and chromatin remodeling was performed using labeled histones H3 and H4 to differentiate between male and female pronuclei. The combination of male and female chromatin appeared to decrease nascent RNA production in the fertilized embryo. This study indicates that paternal chromatin is important in the regulation of transcriptional activity during mouse preimplantation development and that this capacity is acquired during spermiogenesis.
Current progress in oocyte and embryo cryopreservation by slow freezing and vitrification
Authors: Saragusty Joseph , Arav Amir
Published: October 2010

Preservation of female genetics is currently done primarily by means of oocyte and embryo cryopreservation. The field has seen much progress during its four-decade history, progress driven predominantly by research in humans, cows, and mice. Two basic cryopreservation techniques rule the field – controlled-rate freezing, the first to be developed, and vitrification, which, in recent years, has gained a foothold. While much progress has been achieved in human medicine, the cattle industry, and in laboratory animals, this is far from being the case for most other mammals and even less so for other vertebrates. The major strides and obstacles in human and other vertebrate oocyte and embryo cryopreservation will be reviewed here.
Two Pediatric Cases of Multidrug-Resistant Tuberculosis Treated With Linezolid and Moxifloxacin
Authors: Pinon Michele , Scolfaro Carlo , Bignamini Elisabetta , Cordola Giorgio , Esposito Irene , Milano Rosangela , Mignone Federica , Bertaina Chiara , Tovo Pier-Angelo
Published: October 2010

We report here 2 pediatric cases of multidrug-resistant (MDR) tuberculosis (TB) that were observed in Italy. Both families came from an Eastern European country, which is notably an area with a high prevalence of MDR TB. An increase of new cases of MDR TB in developed countries is expected over the next years because of migratory flow, and specific measures and strategies need to be taken to prevent the propagation and dissemination of MDR TB. An efficacious treatment including linezolid and moxifloxacin was administered for 13 months in 1 case. No adverse reactions were detected during close child monitoring. Linezolid and newer fluoroquinolones such as moxifloxacin have been reported to be effective for MDR-TB treatment in adults. On the contrary, there is limited available evidence regarding the effectiveness and safety of these drugs in infants and children with MDR TB. The use of second-line drugs not approved for use in children may be necessary to treat a life-threatening disease such as MDR TB, but it requires careful monitoring to quickly recognize the occurrence of dose- and duration-dependent adverse drug reactions.
Laronidase for Cardiopulmonary Disease in Hurler Syndrome 12 Years After Bone Marrow Transplantation
Authors: Valayannopoulos Vassili , de Blic Jacques , Mahlaoui Nizar , Stos Bertrand , Jaubert Francis , Bonnet Damien , Fischer Alain , de Lonlay Pascale
Published: October 2010

A patient with severe mucopolysaccharidosis type I (Hurler syndrome) underwent bone marrow transplantation twice (at the ages of 2 and 2.5 years), both times with his HLA-identical heterozygous brother as the donor. Between the ages of 10 and 14 years, despite 92% donor engraftment and 50% normal α-l-iduronidase activity, he developed progressive respiratory failure with severe pulmonary arterial hypertension, upper airway obstruction, and interstitial lung disease. Noninvasive ventilation and weekly laronidase therapy were initiated. Within 24 months, his mean pulmonary artery pressure was within the upper limit of normal and interstitial lung disease and airway obstruction improved markedly. He went from using a wheelchair to having full ambulation, he no longer required daytime ventilation, and his quality-of-life scores (Child Health Assessment Questionnaire) significantly improved.
Sexual Behaviors and Sexual Violence: Adolescents With Opposite-, Same-, or Both-Sex Partners
Authors: Pathela Preeti , Schillinger Julia A.
Published: October 2010

OBJECTIVE:

To describe sexual behaviors, sexual violence, and sexual identity among a population-based sample of adolescents according to the sex of their sex partners, considering separately those with partners of both sexes.

METHODS:

From the 2005–2007 New York City Youth Risk Behavior Surveys, 3805 male and 3456 female adolescents reported having had sex and the sex of their sexual contacts. Subgroups were constructed: only opposite-sex partners; only same-sex partners; and partners of both sexes (both-sex partners). Weighted prevalence, risk behaviors (eg, using drugs/alcohol with sex), and sexual identity among subgroups were described.

RESULTS:

Similar numbers of sexually active male (3.2%) and female adolescents (3.2%) reported only same-sex behavior, but fewer male than female adolescents reported both-sex partners (3.7% vs 8.7%; P < .001). Male adolescents with both-sex partners reported a higher prevalence of sexual risk behaviors than male adolescents with only opposite-sex or only same-sex partners. Female adolescents with both-sex or only same-sex partners reported a higher prevalence of risk behaviors than female adolescents with only opposite-sex partners. Adolescents with both-sex partners reported a marked prevalence of dating violence and forced sex. Many adolescents with only same- or both-sex partners (38.9%) self-identified as straight.

CONCLUSIONS:

Of sexually active adolescents, 9.3% reported a same-sex partner, a higher estimate than other published rates. Those who reported both male and female partners reported behaviors that placed them at risk for sexually transmitted infections (STIs), including HIV. Pediatricians and school health providers must inquire about behaviors, not identity, to determine STI risk, and STI education should be appropriate for youth with same-sex partners.
Effects of Resistance Training in Children and Adolescents: A Meta-analysis
Authors: Behringer Michael , vom Heede Andreas , Yue Zengyuan , Mester Joachim
Published: October 2010

CONTEXT:

Although physiologic benefits of resistance training for children and adolescents have been well documented, the impact of age and maturity on trainability of muscle strength remains poorly understood.

OBJECTIVE:

To assess the effects of resistance training in different age groups and maturity levels.

METHODS:

We searched electronic bibliographic databases, key journals, and reference lists of reviews, book chapters, and articles. Two independent reviewers evaluated the effects of resistance training on muscle strength for prepubertal and postpubertal healthy children and adolescents (younger than 18 years) by using the results of randomized and nonrandomized controlled trials. Assessments of muscle endurance and motor performance tests (eg, vertical jump) were excluded. The influence of continuous and categorical moderator variables was assessed by meta-regression and subgroup analyses, respectively.

RESULTS:

The overall weighted effect size of 1.12 (95% confidence interval: 0.9–1.3) was significantly greater than 0 (P < .01). Subgroup analyses revealed “maturity” to be a significant categorical moderator variable (z = 2.50; P = .01) and positive correlation coefficients were found for the continuous variables “duration” (r = 0.28; P = .02) and “frequency” (r = 0.26; P = .03).

CONCLUSIONS:

The results of our analysis indicate that the ability to gain muscular strength seems to increase with age and maturational status, but there is no noticeable boost during puberty. Furthermore, study duration and the number of performed sets were found to have a positive impact on the outcome.
Interpreting Complete Blood Counts Soon After Birth in Newborns at Risk for Sepsis
Authors: Newman Thomas B. , Puopolo Karen M. , Wi Soora , Draper David , Escobar Gabriel J.
Published: October 2010

BACKGROUND:

A complete blood count (CBC) with white blood cell differential is commonly ordered to evaluate newborns at risk for sepsis.

OBJECTIVES:

To quantify how well components of the CBC predict sepsis in the first 72 hours after birth.

METHODS:

For this retrospective cross-sectional study we identified 67 623 term and late-preterm (≥34 weeks gestation) newborns from 12 northern California Kaiser hospitals and 1 Boston, Massachusetts hospital who had a CBC and blood culture within 1 hour of each other at <72 hours of age. We compared CBC results among newborns whose blood cultures were and were not positive and quantified discrimination by using receiver operating characteristic curves and likelihood ratios.

RESULTS:

Blood cultures of 245 infants (3.6 of 1000 tested newborns) were positive. Mean white blood cell (WBC) counts and mean absolute neutrophil counts (ANCs) were lower, and mean proportions of immature neutrophils were higher in newborns with infection; platelet counts did not differ. Discrimination improved with age in the first few hours, especially for WBC counts and ANCs (eg, the area under the receiver operating characteristic curve for WBC counts was 0.52 at <1 hour and 0.87 at ≥4 hours). Both WBC counts and ANCs were most informative when very low (eg, the likelihood ratio for ANC < 1000 was 115 at ≥4 hours). No test was very sensitive; the lowest likelihood ratio (for WBC count ≥ 20 000 at ≥4 hours) was 0.16.

CONCLUSION:

Optimal interpretation of the CBC requires using interval likelihood ratios for the newborn's age in hours.
Reliability of Clinical Examinations for Pediatric Skin and Soft-Tissue Infections
Authors: Marin Jennifer R. , Bilker Warren , Lautenbach Ebbing , Alpern Elizabeth R.
Published: October 2010

OBJECTIVE:

To determine the interrater reliability of clinical examination by pediatric emergency medicine physicians for the diagnosis of skin and soft-tissue infections (SSTIs).

METHODS:

A cross-sectional study of patients presenting to a pediatric emergency department with SSTIs was performed. Each lesion was examined by a treating physician and a study physician (from a pool of 62 physicians) at the bedside during the emergency department visit. The primary outcome was reliability, as measured with the weighted κ statistic, for determining whether the lesion was an abscess and whether the lesion required a drainage procedure.

RESULTS:

A total of 371 lesions were analyzed for interrater reliability. The weighted κ value for diagnosis of the lesion as an abscess was 0.39 (95% confidence interval: 0.32–0.47), and that for assessment of the need for drainage was 0.43 (95% confidence interval: 0.36–0.51). Agreement was statistically more likely for lesions in children ≥4 years of age but was not more likely for lesions in nonblack patients, lesions in patients with a history of or exposure to a close contact with a SSTI, or lesions examined by 2 experienced pediatric emergency medicine physicians.

CONCLUSIONS:

Among the 62 participating physicians at our site, the reliability of the clinical examination was poor. This may indicate that improved education and/or more-objective means for diagnosing these infections in the acute care setting are warranted. Additional studies are needed to determine whether these results are generalizable to other settings.
Novel Cu/Si composites: A sol-gel-derived Al2O3 film as barrier to control interfacial reaction
Authors: Cai Hui , Tong Debao , Wang Yaping , Song Xiaoping , Ding Bingjun
Published: October 2010

Cu/Si composite may be a novel and high-performance material for electronic packaging if the advantages of copper and silicon components are preserved. Because of the severe diffusional reaction between copper and silicon at elevated temperature, efforts are impeded to achieve a bulk Cu/Si composite. Here, by coating a sol-gel-derived Al2O3 film on the Si particle surface, the bulk Cu/Si composites were obtained by the powder metallurgy method. In the prepared Cu/Si composite, Cu forms a continuous matrix while Si particles are homogeneously dispersed in Cu matrix. High-resolution transmission electron microscopy observation indicates that only weak interfacial reaction occurs at the Cu/Al2O3/Si interface and forms a narrow interfacial reaction zone. The thermal diffusivity of the composite at 25 °C is about 30.6 mm2 s−1, over 10 times larger than that of Cu/Si material without Al2O3 film.
Numerical approaches and experimental verification of the conical indentation techniques for residual stress evaluation
Authors: Lee Jin Haeng , Lee Hyungyil , Hyun Hong Chul , Kim Minsoo
Published: October 2010

Conical indentation methods to determine residual stress are proposed by examining the finite element solutions based on the incremental plasticity theory. We first note that hardness depends on the magnitude and sign of residual stress and material properties and can change by up to 20% over a specific range of elastic tensile and compressive residual stress, although some prior indentation studies reported that hardness is hardly affected by residual stress. By analyzing the characteristics of conical indentation, we then select some normalized indentation parameters, which are free from the effect of indenter tip rounding. Adopting dimensional analysis, we present practical conical indentation methods for the evaluation of elastic/plastic equi- and nonequi-biaxial residual stresses. The validity of developed approaches is confirmed by applying them to the experimental evaluation of four-point bending stress.
Control of iron nitride formation by a high magnetic field
Authors: Tong W.P. , Zhang H. , Sun J. , Zuo L. , He J.C. , Lu J.
Published: October 2010

The influence of high magnetic field on nitriding behavior was investigated in a mixture of NH3 and H2. It was found that high magnetic field could shift the equilibrium of nitriding reaction; this proved that the critical nitrogen potential to form γ′-Fe4N and ε-Fe3N phase was evidently enhanced compared with conventional nitriding. This research provides a new approach for a selective nitriding process.
Microstructure and mechanical properties of Ti/AlTiN/Ti-diamondlike carbon composite coatings on steel
Authors: Pang Xiaolu , Yang Huisheng , Shi Shijian , Gao Kewei , Wang Yanbin , Volinsky Alex A.
Published: October 2010

Ti/AlTiN/Ti-diamondlike carbon (DLC) composite coatings were deposited by mid-frequency magnetron sputtering and Hall ion source-assisted deposition on high-speed steel W18Cr4V substrates. The coating microstructure and mechanical properties, including hardness, elastic modulus, coefficient of friction, and wear properties were investigated by scanning electron microscopy, Raman spectroscopy, scratch and ball-on-disk friction tests, respectively. Fairly smooth composite coating with strong interfacial adhesion and good mechanical properties was produced. The substrate bias increases sp3 bonds contents in the DLC layer, thus coating hardness increased from 14 to 24 GPa and elastic modulus from 190 to 230 GPa with the increased substrate bias. Adhesion of interfaces between Ti-DLC and AlTiN layer, AlTiN and the steel substrate decreased with the substrate bias. The coefficient of friction is between 0.10 and 0.15, except when the substrate bias is 500 V, it is 0.2. Composite coating wear resistance increased with the substrate bias.
Processing and electrical properties of Pb0.6Ba0.4Nb2O6 ceramics
Authors: Dursun Sinan , Duran Cihangir
Published: October 2010

Lead barium niobate (PBN or PbxBa1–xNb2O6) is a promising tungsten bronze ceramic system that has a morphotropic phase boundary between the orthorhombic and tetragonal phases at x ≈ 0.63, where the spontaneous polarization (Ps ≈ 60–70 μC/cm2) and other ferroelectric properties are known to be higher. However, even textured PBN60 ceramics have low Ps (∼23.9 μC/cm2) and piezoelectric charge coefficient (d33 ≈ 236 pC/N) as compared to the single crystal counterparts. The aim of this study is to control powder processing, green body formation, and sintering conditions to enhance both densification and electrical properties. Therefore, samples were prepared by tape casting methods using single phase PBN60 and reactive mixture of PbNb2O6 and BaNb2O6 powders. Three wt% excess PbO was found to be necessary for densification. Our results showed that undoped PBN60 ceramics reached Ps = 33 μC/cm2, d33 = 305 pC/N, and had a Tc = 340–350 °C. These results are much higher than the reported values in the literature, which can be attributed to the careful ceramic processing such as tape casting (e.g., homogenous green structure), annealing (e.g., control of excess grain boundary phase), and liquid phase sintering (e.g., higher densification).
Effect of Particle Size of Platinum and Platinum-Cobalt Catalysts on Stability Against Load Cycling
Authors: Matsutani Koichi , Hayakawa Katsuichiro , Tada Tomoyuki
Published: October 2010

To investigate the effect of load cycling, platinum (Pt) and platinum-cobalt (PtCo) fuel cell catalysts with different particle sizes were prepared and evaluated for their durability against load cycling. The particle size of the Pt and PtCo catalysts was controlled by changing the catalyst loading and by applying heat treatment. Pt catalysts with particle sizes of 2–3 nm and 4–5 nm and PtCo catalysts with sizes of 3–4 nm, 4–5 nm and 7–8 nm were obtained. A potential sweep from 0.65 V to 1.05 V was applied to the cathode of membrane electrode assemblies (MEAs) prepared with these catalysts,and the degradation of their mass activity and cell voltage were evaluated. As a result of this investigation, it was found that Pt catalysts with particle sizes of 4–5 nm and PtCo catalysts of particle sizes 7–8 nm showed better stability against potential sweep, with the Pt catalysts of sizes 4–5 nm showing the best stability of all the catalysts tested.
American Archaeology Textbooks as Reflections of the History of the Discipline
Authors: Lyman R. Lee
Published: October 2010

Textbooks introduce students to a discipline's methods and goals. In combination with the desire of publishers to have up-to-date products, each textbook should, hypothetically, reflect the state of the art in a discipline at the time of its publication. Two series of multi-edition textbooks authored by the same individuals confirm the hypothesis for American archaeology that textbooks reflect disciplinary history. These volumes also indicate that textbook series, like much secondary literature, do not provide nuanced and thorough reflections of disciplinary history.
Strategic planning and republicanism
Authors: Mazza Luigi
Published: October 2010

The paper develops two main linked themes: (i) strategic planning reveals in practice limits that are hard to overcome; (ii) a complete planning system is efficacy only in the framework of a republican political, social and government culture. It is argued that the growing disappointment associated to strategic planning practices, may be due to excessive expectations, and the difficulties encountered by strategic planning are traced to three main issues: (a) the relationship between politics and planning; (b) the relationship between government and governance; and (c) the relationship between space and socioeconomic development. Some authors recently supported an idea of development as consisting in the qualitative evolution of forms of social rationality and argued that a reflection about the relationships between physical transformations and visions of development could be a way of testing innovations. But such strong demands might be satisfied only if we manage to make a 'new social and territorial pact for development', recreating a social fabric imbued with shared values. The re-creation of a social fabric imbued with shared values requires a rich conception of the political community and the possibility that the moral purposes of the community may be incorporated by the state. All this is missing today. Outside a republican scheme planning activities are principally instruments for legitimising vested interests and facilitating their investments, and the resolution of the conflicts that arise between the planning decisions of the various levels of government becomes at least impracticable. A complete planning system can be practised if can be referred to the authority and syntheses expressed in and by statehood, which suggests that in a democratic system planning is republican by necessity rather than by choice.
Transformation of the New Belgrade urban tissue: Filling the space instead of interpolation
Authors: Maric Igor , Nikovic Ana , Manic Bozidar
Published: October 2010

This paper points to current transformations of the New Belgrade architectural and urban space identifying the process of filling the empty undeveloped areas within the New Belgrade blocks under the pressure of new commercial facilities. Given that these changes are not regulated by plans in an appropriate way, they are manifested in the space as problem situations leading to the production of space which is appropriate for the narrow interests of capital holders, while interests of direct users, as well as interest of a wider public, are most often neglected. The paper presents a critical analysis of the existing conditions and identifies problems emerging in the development and planning of the New Belgrade urban tissue. The space transformations have been explored at the level of urban and physical structure, urban landscape and user's life. Identified problem situations are indicative for further consideration of strategies for urban-architectural planning and design of New Belgrade.
Development, characteristics and comparative structural analysis of tensegrity type cable domes
Authors: Nenadovic Aleksandra
Published: October 2010

Tensegrity type cable domes are three-dimensional structural configurations, prestressed inside the perimeter compression ring, in which the continuous tension throughout the roof structure is made by continuous tension cables and discontinuous compression struts. These kinds of structures can be formed like spatially triangulated networks or like networks nontriangulated in space. This paper examines some effects of network geometry on the behaviour and structural efficiency of tensegrity type cable domes. In this paper the roof cover is considered non-interactive with the supporting structure, unlike rigidly clad tensegrity type cable domes. Since the main bearing elements of tensegrity type cable domes are prestressed cables, they show non-linear load deformation and rely upon geometric stiffness. A geometrically non-linear analysis of non-triangulated and triangulated structures for different load conditions was conducted employing a computer program based on the perturbation theory. The incrementally-iterative procedure, with an approximation of the stiffness matrix by combining the elastic and geometric stiffness matrix, allows detection of structural instabilities.
The polycystic ovary syndrome (pcos) status and cardiovascular risk in young women
Authors: Ilie Ioana , Pepene Carmen , Marian Ioan , Mocan Teodora , Hazi Georgeta , Drăgotoiu Gheorghe , Ilie Razvan , Mocan Lucian , Duncea Ileana
Published: October 2010

The study investigated the presence of early vascular damage and chronic inflammation, and their relationships with hormonal and metabolic parameters in 45 young women with PCOS in comparison with thirty-two healthy age-matched controls. Hormonal and metabolic profiles, high sensitivity C-reactive protein (hsCRP), tumoral necrosis factor-alpha (TNF-α), endothelin-1 (ET-1), brachial flow-mediated vasodilation (FMD) and carotid intima-media thickness (CIMT) were determined in both groups. Compared with the controls, women with PCOS had significantly lower FMD and respectively higher ET-1 levels (p=0.001). No differences were observed between the groups in terms of CIMT or inflammatory markers. In the PCOS group, ET-1 levels were significantly correlated with only testosterone concentrations (r = 0.31, p = 0.037), whereas the hsCRP levels were independently predicted only by body mass index (BMI). Within the total group, the PCOS status was the sole significant predictor of ET-1 levels and the only independent predictor of FMD. In conclusion, there is evidence of endothelial dysfunction associated with increased levels of androgen hormones in young women with PCOS. The combination of endothelial dysfunction and coexistent obesity promoting inflammation contributes to the progression of atherogenesis in PCOS. The PCOS status should be regarded as a predictor marker of cardiovascular risk, along with well-known cardiovascular risk factors.
Postpartum examination, breastfeeding, and contraception in the postpartum period in the Czech Republic
Authors: Zahumensky Jozef , Sykorova Jana , Sottner Oldrich , Zmrhalova Barbora , Vojtech Jiri , Menzlova Erika , Vasicka Ian , Dvorska Monika , Maxova Katerina , Vlacil Jaromir , Hrubantova Helena , Halaska Michael
Published: October 2010

In the majority of recent textbooks of obstetrics, a routine follow-up examination at the end of the postpartum period is recommended. To date, no studies have been done in the Czech Republic addressing use of contraception and follow-up care in the postpartum period. Questionnaires were sent to 672 participants who gave birth in the year 2008, inquiring about follow-up examinations in the postpartum period and use of contraception. In total, 458 (68.2%) questionnaires were returned. 430 women (93.9%) underwent routine examinations at 6 weeks into the postpartum period. At the time of examination, 36 women were asked about their particular health problems (8.4%). In 130 instances, the question most often addressed by the outpatient gynecologist concerned use of contraception (30.2%). However, only 34 physicians expressed concern about changes in sexual life or other sexually related problems. 426 women (93.0%) were sexually active and 310 women (72.8%) did not use any contraception with the exception of breastfeeding. The current practice of outpatient gynecological visits at 6 weeks postpartum and advice on contraception both seem inadequate.
Numerical analysis of absorption and transmission photoacoustic spectra of silicon samples with differently treated surfaces
Authors: Maliński M. , Chrobak Ł.
Published: October 2010

This paper presents results of the photoacoustic (PA) spectral studies, of a series of silicon samples with differently prepared surfaces, in two PA experimental configurations, so-called, absorption and transmission ones. The PA amplitude spectra of the samples indicated existence of the damaged surface layers. In the paper, the two layer mathematical models of a sample with a damaged surface layer that were used for numerical interpretation of the amplitude PA spectra of the investigated samples, are presented and discussed.
Concealment from predators drives foraging habitat selection in brood‐rearing Alpine black grouse Tetrao tetrix hens: habitat management implications
Authors: Signorell Natalina , Wirthner Sven , Patthey Patrick , Schranz Rebekka , Rotelli Luca , Arlettaz Raphaël
Published: October 2010

Declines of Alpine black grouse Tetrao tetrix populations have been linked to increasing disturbance by recreation and degradation of breeding habitat due to changes in land‐use, especially abandonment of traditional farming practices. Appropriate forest, shrubland and grassland management may mitigate the negative effects of land abandonment. The habitat associations and trophic requirements of brood‐rearing Alpine black grouse hens were appraised to inform effective habitat management policies. We measured the abundance, biomass and phenology of arthropods, a key food source for grouse chicks, in eight timberline habitat categories and performed a habitat selection analysis based on radio‐tracking data collected from eight brood‐rearing hens in the Swiss and Italian Alps. Arthropod biomass differed significantly between habitat categories and peaked in early summer due to a sharp increase of orthopterans (Saltatoria), an essential food source for Alpine black grouse chicks. Open grassland and grassy shrubland yielded the highest arthropod biomass, with Saltatoria dominating the sample. Yet, brood‐rearing hens avoided open grassland, opting for a mosaic of grassy shrubland with scattered trees. Chick‐rearing hens apparently traded‐off food abundance for reduced predation risk, i.e. habitats offering cover for concealment and escape from predators. These specific black grouse breeding habitat requirements inform about habitat management within Alpine timberline ecosystems. Managers should not restore extensive, homogeneous pasturelands. Instead, a complex heterogeneous habitat mosaic, consisting of patches of grassland and shrubland interspersed with scattered coniferous trees should be promoted.
A method for inferring extinction based on sighting records that change in frequency over time
Authors: Jarić Ivan , Ebenhard Torbjörn
Published: October 2010

It is a very important, but also a very difficult task, to establish how long a certain species has to remain unregistered before we can declare it extinct. The wrong assumption regarding species extinction could result in a type I or type II statistical error, leading to inappropriate management actions or even species extinction. Recent development of the methods for inferring the threat of extinction, when the only available information is a record of sightings, has enabled a quantitative approach to the problem. In our study we present an index that infers extinction probability based on trends in sighting intervals. Our study comprises a description of the sighting trend index, a sensitivity analysis and an application of the index to the sighting record of the black‐footed ferret Mustela nigripes. The main advantage of this method could be its sensitivity to changes in sighting frequency within the sighting record. However, further testing of the method on different data sets could be important for gaining additional knowledge regarding its adequate application in the field of conservation biology.
Public Transit Network Connectivity
Authors: Hadas Yuval , Ceder Avishai (Avi)
Published: October 2010

The service reliability of public transit operations is gaining increased attention as agencies face immediate problems in providing credible service and attempting to reduce operational cost. Unreliable service has been cited as the major deterrent element for existing and potential passengers. Because most public transit attributes are of a stochastic nature—travel time, dwell time, demand, and so forth—the passenger is likely to experience unplanned waiting and riding times. Missed transfers are major contributors to the reliability issues of any transit system; therefore, this work focuses on the connectivity of the transit network with the reliability and comfort of transfers in multilegged trips. Because of the physical and spatial characteristics of the transit routes, it is possible to categorize the transfers into three types: nonadjacent transfer points, adjacent transfer points, and shared transfer points. Each type of transfer contributes differently to the degree of connectivity of the transit system. On the basis of transit network of routes, spatial-based performance indicators are introduced and defined. That is followed by results of a case study of the transit networks of two Israeli midsize cities.
What Determines Soft Costs in Major Public Transit Fixed Guideway Projects?
Authors: Antos Justin D. , Peskin Robert L. , Tomeh Osama , Schneck Donald C. , Touran Ali , Bravo Raul V. , Laver Richard
Published: October 2010

Soft costs in major public transportation fixed guideway projects generally account for about 20% of the project's capital cost, but wide variation in the relative magnitude of soft costs can make them a major factor in the public deliberation over whether to build a transit project. In addition, soft costs are often poorly understood and have varied considerably more than industry estimation techniques predicted. This paper examines the actual capital expenditures from 59 U.S. light and heavy rail projects and seeks to explain the wide variance in soft costs (from 11% to 54% of construction costs) by analyzing project characteristics such as complexity, physical attributes, sponsor agency traits, and the circumstances of project development. The analysis develops a multivariate regression establishing a cost relationship between 10 project characteristics and resulting soft costs as a percentage of “hard” (construction) costs. These results can be used to make more accurate estimates of soft costs for future projects.
Development of Data-Processing Framework for Transit Performance Analysis
Authors: Liao Chen-Fu , Liu Henry X.
Published: October 2010

A methodological data-processing framework is developed to process a massive amount of transit data, including vehicle location, passenger count, and electronic fare transactions. The developed data analysis methodology can allow a number of applications, such as transit route performance measurement, to support decision making for transit planning and operation. The data analysis methodology is demonstrated by the use of 1 month of archived transit data obtained from Metro Transit in the Twin Cities of Minnesota. A route-based transit performance analysis at time point level is discussed to evaluate route running time and schedule adherence. An application interface was developed to analyze bus adherence at time points and link travel time performance. The data-processing framework has the capability to support studies on transfer activities and transit rider's origin and destination inference. The developed data analysis methodology has demonstrated its capability to analyze transit performance and to support further research on other intelligent transit applications.
Levels of Overcrowding in Bus System of Dhaka, Bangladesh
Authors: Katz Donald , Rahman Md. Mizanur
Published: October 2010

Overcrowded buses are a common sight in Dhaka, Bangladesh, as they swerve between rickshaws and auto-rickshaws and blare their horns, with the next stop announced by a shout. Two primary bus services operate in the city, ticketed and local, differing in fare collection, stop patterns, and price. They carry the largest share of trips in Dhaka, and both are overcrowded. Understanding the differences between the two, and how crowding affects their curbside operations, could show which is the more effective way of moving passengers. A method to evaluate a system that seems disorderly from the outside was developed, and the effects that crowded conditions have on performance were studied. Data were collected during a half-year period through onboard studies of bus dwell times and loads the buses carry. Despite the uncomfortable conditions crowded buses create for passengers, the buses operate more efficiently for the volumes carried. Local buses in particular were shown to be more effective in transporting the population. Still, Dhaka must live with overcrowded buses until a mass transit system to relieve overcrowding can be built.
More Comfort, Shorter Travel Time, or Low Fares?
Authors: Ohnmacht Timo , Scherer Milena
Published: October 2010

This paper, by controlling for other covariants, examines how the needs and preferences of transit users for more comfort, shorter travel times, or low fares vary across different trip purposes, such as education, work, holiday, leisure, business, and shopping. The fieldwork for this research effort was undertaken in central Switzerland on a scenic railway route. The logit modeling approach shows the following preliminary findings: Shorter travel times are most preferred by business travelers, followed by those traveling for educational and work purposes. Leisure and holiday travelers are more sensitive to low fares than to comfort. There is a strong age effect; for leisure travel elderly people tend to prefer comfort more than a low fare. Transport decision makers could balance system needs with customer expectations and incorporate these factors into transport and marketing planning.
Defining a Primary Market and Estimating Demand for Major Bicycle-Sharing Program in Philadelphia, Pennsylvania
Authors: Krykewycz Gregory R. , Puchalsky Christopher M. , Rocks Joshua , Bonnette Brittany , Jaskiewicz Frank
Published: October 2010

Public bicycle-sharing (bike share) programs have become increasingly popular in recent years, particularly in Europe, with a number of cities recently implementing systems and high levels of usage. North American efforts have been more limited to date, with high-profile recent examples including a small program in Washington, D.C., and a substantial seasonal program in Montreal, Canada. Because there are no established large-scale programs in the United States, planners exploring potential system designs and feasibilities are faced with an unusual degree of uncertainty about who would ride, where they might ride, and how often they might ride. A large-scale bike share system is under consideration in Philadelphia, Pennsylvania. This paper discusses the methods and findings of a two-phase project that (a) used a raster-based geographic information system analysis to identify a primary geographic market area for a bike share program and (b) applied bike share trip diversion rates observed in peer European cities to estimate daily bike share trips in the primary market area. This analysis resulted in estimates for daily usage in Philadelphia that ranged from roughly 6,000 to 23,000 for two scales of market area and three demand scenarios (low, middle, and high). As bike share systems continue to proliferate in different settings, new data can refine the methods used here to provide increasing levels of certainty in the future.
Impact of Carsharing on Household Vehicle Holdings
Authors: Martin Elliot , Shaheen Susan A. , Lidicker Jeffrey
Published: October 2010

Carsharing has grown considerably in North America during the past decade and has flourished in metropolitan regions across the United States and Canada. The new transportation landscape offers urban residents an alternative to automobility, one without car ownership. As car-sharing has expanded, there has been a growing demand to understand its environmental effects. This paper presents the results of a North American carsharing member survey (N = 6,281). A before-and-after analytical design is established with a focus on carsharing's effects on household vehicle holdings and the aggregate vehicle population. The results show that carsharing members reduce their vehicle holdings to a degree that is statistically significant. The average number of vehicles per household of the sample drops from 0.47 to 0.24. Most of this shift constitutes one-car households becoming carless. The average fuel economy of carsharing vehicles used most often by respondents is 10 mi/gal more efficient than the average vehicle shed by respondents. The median age of vehicles shed by carsharing households is 11 years, but the distribution covers a considerable range. An aggregate analysis suggests that carsharing has taken between 90,000 and 130,000 vehicles off the road. This equates to 9 to 13 vehicles (including shed autos and postponed auto purchases) taken off the road for each carsharing vehicle.
Global Positioning System Integrated with Personalized Real-Time Transit Information from Automatic Vehicle Location
Authors: Barbeau Sean J. , Georggi Nevine L. , Winters Philip L.
Published: October 2010

Navigation of a transit system can be a major obstacle to new riders, especially special-needs populations and tourists. For those with cognitive disabilities (approximately 14.3 million Americans, or 6% of the population), it is challenging to plan and execute a trip without assistance. A travel assistance device (TAD) software prototype for Global Positioning System–enabled phones was developed to aid new transit riders, especially those who are cognitively disabled. When riders approach their stops, the TAD vibrates and delivers audio and visual messages to the riders to request a stop and exit the vehicle. This paper reports the results of a study that integrated communication with an automatic vehicle location (AVL) system on transit vehicles into TAD, with new features, including personalized notices of estimated vehicle arrival time and of vehicle arrival. Implementation issues addressed include the limitations of accessing AVL data for real-time consumer use, integration of different transit agency data sources, and consideration of the effects of software applications (e.g., wireless data communication) on mobile phone functionality (e.g., battery life).
Travel Behavior Patterns of Different Socially Disadvantaged Groups
Authors: Dodson Jago , Burke Matthew , Evans Rick , Gleeson Brendan , Sipe Neil
Published: October 2010

This paper contributes to the understanding of transport disadvantage and the transport dimensions of environmental justice by investigating the travel behavior patterns of socially disadvantaged groups by using household travel survey data. The study described in this paper goes beyond determining the basic descriptive statistics that are commonly reported in this area of research and instead uses cluster analysis to identify socially disadvantaged households. The study then uses the six clusters generated by the analysis to identify the differences in the travel behaviors between these groups. The paper shows considerable differences in travel behavior between socially disadvantaged households that must be recognized if scholars and policy makers are to describe and respond adequately to the experience of transport disadvantage for these groups. The paper concludes with some comparative observations about the travel behavior of the disadvantaged population in dispersed rapidly growing regions and the wider implications for ensuring environmental justice in transport.
Americans' Time Use
Authors: Whitehead-Frei Charlotte , Kockelman Kara M.
Published: October 2010

This paper describes a model of Americans' time use in which time spent with children in home and out of home influences activity and travel time allocation. Although the activities and travel of children are studied more in depth now than in the past, to date few studies have examined the time spent with children as a dependent variable within a time use model. Most existing models of activity and travel participation allocate time-to-work activities, followed by obligatory maintenance activities and nonobligatory discretionary activities. The model described in this paper expands the data into eight activity categories to determine whether these activities are more or less necessary than past research assumed. The results suggest that the total amount of time spent inside the home with children has a statistically significant and negative impact on work, leisure, and personal activities inside the home, but work duration and work travel have no significant or practical impact on time spent with children, everything else being constant. There is also some indication that more time spent in in-home activities is associated with greater travel time expenditures. Overall, the 2007 American Time Use Survey contains a variety of details that help illuminate the answers to many such questions.
Safeguarding Minority Civil Rights and Environmental Justice in Service Delivery and Reductions
Authors: Reddy Alla , Chennadu Thomas , Lu Alex
Published: October 2010

Federal civil rights and environmental justice (EJ) mandates require transit agencies to provide service without racial or income discrimination and to ensure meaningful access by individuals with limited English proficiency. EJ research generally focuses on long-range planning and capital investment decision making. However, for operating agencies, equity in scheduling, service planning, and tactical service delivery operations is critical to compliance with Title VI legislation and FTA Circular C4702.1A. In 2009, New York City Transit (NYCT) designed a service reductions package in response to the economic downturn. EJ considerations were integral to its planning. The use of ridership performance criteria for route selection resulted in fewer impacts on routes with heavily minority or low-income populations. Quantitative analysis ensured that protected demographics were not significantly adversely affected by proposed service rationalizations. Route and frequency modifications and service span changes were evaluated with statistical t-tests during programming stages, resulting in proposals sensitive to equity concerns. Operationally, NYCT actively monitors service using U.S. census, survey, and routine agency data. The t-test and the chi-square test explicitly demonstrate racial and income equity in all aspects of agency operations on the basis of service standards and policies. As an example, t-tests compared the observed load factors with published guidelines; no significant differences in service delivery between demographic groups were found.
Performance Measurement Frameworks and Development of Effective Sustainable Transport Strategies and Indicators
Authors: Pei Yi Lin , Amekudzi Adjo A. , Meyer Michael D. , Barrella Elise M. , Ross Catherine L.
Published: October 2010

This paper identifies seven attributes of robust performance measurement systems by analyzing five performance measurement frameworks and their use of transportation system performance indicators. The attributes are then used to examine three case studies from Europe and the United States to demonstrate the value of performance measurement frameworks for developing and improving sustainable transportation strategies and indicators. The case studies point to important considerations in formulating a robust sustainable transportation strategy at different levels of governance and also indicate the importance of ensuring alignment in an agency's vision, objectives, and monitoring systems. The characteristics of an effective framework for the development of sustainable transportation strategies include a comprehensive sustainability objective, a good connection to the goals and objectives of an agency, and vertical and horizontal integration. In addition, a framework should capture the interactions among variables, reflect stakeholder perspectives, and consider the capabilities and constraints of the agency and should be flexible to foster self-learning.