bluuebunny/crossref_metadata_2025 huggingface dataset:
DRD4Genotype Predicts Longevity in Mouse and Human
Authors: Grady Deborah L. , Thanos Panayotis K. , Corrada Maria M. , Barnett Jeffrey C. , Ciobanu Valentina , Shustarovich Diana , Napoli Anthony , Moyzis Alexandra G. , Grandy David , Rubinstein Marcelo , Wang Gene-Jack , Kawas Claudia H. , Chen Chuansheng , Dong Qi , Wang Eric , Volkow Nora D. , Moyzis Robert K.
Published: January 2013

Longevity is influenced by genetic and environmental factors. The brain's dopamine system may be particularly relevant, since it modulates traits (e.g., sensitivity to reward, incentive motivation, sustained effort) that impact behavioral responses to the environment. In particular, the dopamine D4 receptor (DRD4) has been shown to moderate the impact of environments on behavior and health. We tested the hypothesis that theDRD4gene influences longevity and that its impact is mediated through environmental effects. Surviving participants of a 30-year-old population-based health survey (N= 310; age range, 90–109 years; the 90+ Study) were genotyped/resequenced at theDRD4gene and compared with a European ancestry-matched younger population (N= 2902; age range, 7–45 years). We found that the oldest-old population had a 66% increase in individuals carrying theDRD47R allele relative to the younger sample (p= 3.5 × 10−9), and that this genotype was strongly correlated with increased levels of physical activity. Consistent with these results,DRD4knock-out mice, when compared with wild-type and heterozygous mice, displayed a 7–9.7% decrease in lifespan, reduced spontaneous locomotor activity, and no lifespan increase when reared in an enriched environment. These results support the hypothesis thatDRD4gene variants contribute to longevity in humans and in mice, and suggest that this effect is mediated by shaping behavioral responses to the environment.
Functional Differentiation of a Population of Electrically Coupled Heterogeneous Elements in a Microcircuit
Authors: Sasaki Kosei , Cropper Elizabeth C. , Weiss Klaudiusz R. , Jing Jian
Published: January 2013

Although electrical coupling is present in many microcircuits, the extent to which it will determine neuronal firing patterns and network activity remains poorly understood. This is particularly true when the coupling is present in a population of heterogeneous, or intrinsically distinct, circuit elements. We examine this question in theAplysia californicafeeding motor network in five electrically coupled identified cells, B64, B4/5, B70, B51, and a newly identified interneuron B71. These neurons exhibit distinct activity patterns during the radula retraction phase of motor programs. In a subset of motor programs, retraction can be flexibly extended by adding a phase of network activity (hyper-retraction). This is manifested most prominently as an additional burst in the radula closure motoneuron B8. Two neurons that excite B8 (B51 and B71) and one that inhibits it (B70) are active during hyper-retraction. Consistent with their near synchronous firing, B51 and B71 showed one of the strongest coupling ratios in this group of neurons. Nonetheless, by manipulating their activity, we found that B51 preferentially acted as a driver of B64/B71 activity, whereas B71 played a larger role in driving B8 activity. In contrast, B70 was weakly coupled to other neurons and its inhibition of B8 counteracted the excitatory drive to B8. Finally, the distinct firing patterns of the electrically coupled neurons were fine-tuned by their intrinsic properties and the largely chemical cross-inhibition between some of them. Thus, the small microcircuit of theAplysiafeeding network is advantageous in understanding how a population of electrically coupled heterogeneous neurons may fulfill specific network functions.
How Did Work Attitudes Change in Reform-Era China? Age, Period, and Cohort Effects on Work Centrality
Authors: Kwon Soyoung , Schafer Markus H.
Published: January 2013

Using a four-wave cross-sectional repeated dataset spanning 17 years (World Value Survey, 1990, 1995, 2000, 2007), this research examines changes in work centrality in China during the period of economic reform. The article utilizes a recently developed methodology, hierarchical age-period-cohort (HAPC) models, to disentangle the effects of age, period, and cohort. Results show that age has a curvilinear effect: work centrality increases up to middle age, then levels off. For period effects, there is a downward trend in work centrality in China between the 1990s and 2000s that is explained by economic growth. Though overall cohort effects are marginally significant, the study reveals that work centrality tends to be high among the “revolutionary socialism generation” but lower for the “post-800 generation.”
Minimum Wage and Mexican and Central American Influx
Authors: Von Scheven Elsa , Light Ivan
Published: January 2013

In the 1990s, thirteen American states raised their minimum wage above the federal level, while the other thirty-five contiguous states retained the lower federal standard. An increased minimum wage should reduce employment among the lowest-paid workers, and therefore reduce their influx. Using individual-level data from the 5% Public Use Sample of the 2000 U.S. Census of Population, this research examines the effects of forty-eight contiguous U.S. states' minimum wage policies on the settlement choices of recently arrived Mexican and Central American immigrants. As predicted, the authors found that these Mexican and Central American immigrants were less likely to settle in states that implemented above-federal minimum wages during the 1990s as opposed to settling in states that retained the federal-level minimum wage during that decade. Conversely, states' minimum wage policies had no effect upon the influx of recent immigrants from other countries. These results suggest that states can influence the influx of low-wage immigrants by adjusting their minimum wage.
The Enduring Impact of Race: Understanding Disparities in Student Disciplinary Infractions and Achievement
Authors: Beck Audrey N. , Muschkin Clara G.
Published: January 2013

To what extent do persistent race gaps in educational outcomes stem from differences in the level of advantage that students bring to school or from differences in opportunities to succeed? In order to disentangle the component elements of race gaps in middle school achievement and disciplinary infractions, the authors use demographic methods that quantify the proportion of the race gap that is linked to the student, peer, and school composition of race groups. Using administrative school records from North Carolina, the authors find that (1) students' family and demographic characteristics are the most important explanatory factors; (2) the distribution of students across schools with differing racial composition, school sizes, teacher qualifications, and poverty levels also contributes to explaining the gaps; but (3) a substantial portion of each race gap remains unexplained by these compositional differences.
Combining methods in the assessment and analysis of communication in aphasia
Authors: Saldert Charlotta , Bergman Malin , Holstensson Josefin , Jönsson Sara , Nygren Klara , Vennman Frida , Ferm Ulrika
Published: January 2013

In this case study the benefit of using analysis of conversational interaction in clinical assessment of communication is explored. A diagnostic test revealed a severe global aphasia in a man. However, according to a questionnaire filled out by the wife, her husband had some functional communication. The description of the consequences of aphasia in this man was further modified and enriched by analyses of conversational interaction between the man and his spouse. The Measure of Participation in Conversation and the Measure of Skill in Supported Conversation show that the couple has strategies that facilitate communication. Activity-based Communication Analysis provides information about how the strategies are used and about the influence of different factors brought into the interaction by the situation and the individuals involved. Thus, although time consuming, analysis of natural conversations provide valid information that is of importance in assessment of communication and implementation of intervention that can have an impact on everyday life in persons with aphasia and their conversation partners.
The relationship between language skills and interactional skills in children with language impairment
Authors: Bruce Barbro , Nettelbladt Ulrika , Hansson Kristina
Published: January 2013

This study investigates interaction in dialogues between children with language impairment (LI) and peers of different ages and at two different times, taking into account the language skills of the children with LI. The hypotheses tested were that dialogues between more mature children are more coherent and that the degree of language problems of the child with LI is not directly associated with characteristics of the dialogues. Nine children with LI (aged 3;9–5;0 at time I) were recorded with an age-similar and a language-similar peer on two occasions with a one-year interval. The analysis focused on responsiveness and assertiveness in the dialogues as wholes. Dialogues between older children were more coherent and mutual influence within the dialogues was significant at both times. The children with LI tended to be more assertive with the younger peer. The language skills of the children with LI only partly explained the characteristics of the dialogues. Intervention for children with LI should focus on enhancing their opportunities to interact with peers of different ages.
“One gets along enough to make it work”
Authors: Pajo Kati
Published: January 2013

Few studies have been focused on the local contexts in the conversation prior to hearing-impaired (HI) individuals’ ‘What?’ and ‘Where?’ type clarification requests, other-initiations of repair (OI-actions). To address this gap, the present study utilized conversation analysis (CA) and video recordings of one married couple (a severely to profoundly HI individual and his spouse) as data. The analysis revealed that OIactions occurred in irregular frequency and that the HI recipient utilized OI-actions as any interactant, but the ability of the HI recipient to continue a conversation was susceptible to distraction. Several local contexts at risk for HI recipient as well as other reasons for the HI individual to use OI-actions were found. Furthermore, the analysis revealed what type of OI-actions were used in certain contexts. This study suggests that clinicians adopt an interaction orientation that is client-pair centred and further, that they incorporate an intervention that is oriented to conversation in their clinical work.
Structure and Process - Influence of Historical Agriculture of Linear Flow Paths by Extreme Rainfall in Brandenburg
Authors: Deumlich Detlef
Published: January 2013

Long-term erosion forecast can completely misinterpret in extreme events in plain regions. Flow paths are well represented in the plain using digital elevation models in the 1-m grid (DEM1). The scale of the erosion process models and the elevation models is comparable. With it instruments are available to improve the erosion simulation. Simulations, based on (R)USLE family and bigger grid width, are relevant for regional overviews, to the clarification of small scale relevant linear erosion forms, however, unsuitably. The cross-slope tillage has intensified the water erosion in the examined case with special area morphology. From historical sources furrows of the ridge and furrow system were identified as runoff ways. Historical and actual information sources allowed the clarification of especially regional erosion events. Site specific and climatic factors as well as the actual land management caused a high damage magnitude in particular with extreme rainstorms, modified by historical land use structures.
Interhemispheric transcallosal route for resection of anterior third ventricular lesions
Authors: Cohen-Gadol Aaron A.
Published: January 2013

Anterior third ventricular lesions present with a variety of symptoms related to cerebrospinal fluid flow obstruction and mass effect. Colloid cysts are among the most common lesions in the region. They usually present with ventriculomegaly, leading to headaches, vertigo, or, rarely, decreased mental status due to the development of acute hydrocephalus. Many patients become aware of their asymptomatic colloid cysts during imaging evaluation related to other conditions. Symptomatic cysts require removal, and larger asymptomatic colloid cysts (> 1cm) in younger patients may also need to be excised despite a lack of symptoms.

A variety of surgical routes have been described to access and remove colloid cysts. Endoscopic approaches are least invasive and provide adequate decompression and removal of the cyst wall. However, presence of ventriculomagaly may be necessary to provide adequate working space for endoscopic resection. Transcallosal interhemispheric and transcortical routes are typically reserved for patients with symptomatic or large asymptomatic cysts without any significant hydrocephalus. Transcortical route may carry a slightly increased risk of seizures due to cortical disruption. Interhemispheric transcallosal approach with the use of microsurgical techniques minimizes injury to normal structures. In this video, the author describes his technique for transcallosal resection of a large colloid cyst in the absence of significant ventriculomegaly. Methods to minimize complications are reviewed.

The video can be found here: http://youtu.be/KzC8QYsTKeg.
Interhemispheric transcallosal approach for resection of intraventricular central neurocytoma
Authors: Liu James K.
Published: January 2013

The interhemispheric transcallosal approach is a versatile approach to access intraventricular tumors of the lateral and third ventricles. The advantages of using a transcallosal approach over a classical transcortical approach include a direct midline orientation with symmetrical access to both lateral ventricles and both walls of the third ventricle. In addition, violation of the cerebral cortex and the risk of postoperative seizures can be avoided. Central neurocytomas are rare benign tumors that represent approximately 0.1 to 0.5% of all primary brain tumors. They are typically located in the lateral ventricles and tend to present clinically with hydrocephalus. Currently, surgical removal with a gross-total resection is the treatment of choice. In this operative video manuscript, the author demonstrates an illustrative step-by-step technique for microsurgical resection of a large central neurocytoma involving both lateral ventricles in a patient with hydrocephalus using the interhemispheric transcallosal approach. A complete removal was performed without the need for permanent shunting. The operative technique and surgical nuances, including the surgical approach, intraventricular tumor removal, and closure are illustrated in this video atlas.

The video can be found here: http://youtu.be/KzC8QYsTKeg.
BRCA1 and Its Network of Interacting Partners
Authors: Christou Charita , Kyriacou Kyriacos
Published: January 2013

BRCA1 is a large multi-domain protein with a pivotal role in maintaining genome stability and cell cycle progression. Germline mutations in the BRCA1 gene confer an estimated lifetime risk of 60%–80% for breast cancer and 15%–60% for ovarian cancer. Many of the germline mutations associated with cancer development are concentrated in the amino terminal RING domain and the carboxyl terminal BRCT motifs of BRCA1, which are the most well-characterized regions of the protein. The function of BRCA1 in DNA repair, transcription and cell cycle control through the DNA damage response is orchestrated through its association with an impressive repertoire of protein complexes. The association of BRCA1 with ATM/ATR, CHK2 and Aurora A protein kinases regulates cell cycle progression, whilst its association with RAD51 has a direct impact on the repair of double strand DNA breaks (DSBs) by homologous recombination (HR). BRCA1 interactions with the MRN complex of proteins, with the BRCC complex of proteins that exhibit E3 ligase activity and with the phosphor proteins CtIP, BACH1 (BRIP1) and Abraxas (CCDC98) are also implicated in DNA repair mechanisms and cell cycle checkpoint control. BRCA1 through its association with specific proteins and multi-protein complexes is a sentinel of the normal cell cycle control and DNA repair.
Variable DC-Link Voltage Algorithm with a Wide Range of Maximum Power Point Tracking for a Two-String PV System
Authors: Lee June-Seok , Lee Kyo
Published: January 2013

This paper proposes a variable DC-link reference voltage algorithm for wide range of maximum power point tracking (MPPT) for two-string photovoltaic (PV) systems. A multi-string system, which is a kind of PV system, is widely used due to its many merits (such as the ability to use low rating devices, high MPPT efficiency, and so forth). PV systems can choose their input voltages on the basis of their PV cell connection structure. The PV cell connection structure can be restricted because the input voltage and current affect the PV system design. This reduces the MPPT range under some weather conditions. In the restricted PV connection structure, this algorithm enlarges the MPPT range and minimizes the increment of the total harmonic distortion (THD) by selecting the appropriate DC-link voltage reference which is changed by comparing the sorted input voltage. To verify the proposed algorithm, simulation and experiments are conducted to show the results of the performance for the proposed algorithm.
Second-Order Harmonic Reduction Technique for Photovoltaic Power Conditioning Systems Using a Proportional-Resonant Controller
Authors: Jeong Hae-Gwang , Kim Gwang-Seob , Lee Kyo-Beum
Published: January 2013

This paper proposes a second-order harmonic reduction technique using a proportional-resonant (PR) controller for a photovoltaic (PV) power conditioning system (PCS). In a grid-connected single-phase system, inverters create a second-order harmonic at twice the fundamental frequency. A ripple component unsettles the operating points of the PV array and deteriorates the operation of the maximum power point tracking (MPPT) technique. The second-order harmonic component in PV PCS is analyzed using an equivalent circuit of the DC/DC converter and the DC/AC inverter. A new feed-forward compensation technique using a PR controller for ripple reduction is proposed. The proposed algorithm is advantageous in that additional devices are not required and complex calculations are unnecessary. Therefore, this method is cost-effective and simple to implement. The proposed feed-forward compensation technique is verified by simulation and experimental results.
Burning Behaviour of High-Pressure CH4-H2-Air Mixtures
Authors: Moccia Vincenzo , D'Alessio Jacopo
Published: January 2013

Experimental characterization of the burning behavior of gaseous mixtures has been carried out, analyzing spherical expanding flames. Tests were performed in the Device for Hydrogen-Air Reaction Mode Analysis (DHARMA) laboratory of Istituto Motori—CNR. Based on a high-pressure, constant-volume bomb, the activity is aimed at populating a systematic database on the burning properties of CH4, H2 and other species of interest, in conditions typical of internal combustion (i.c.) engines and gas turbines. High-speed shadowgraph is used to record the flame growth, allowing to infer the laminar burning parameters and the flame stability properties. Mixtures of CH4, H2 and air have been analyzed at initial temperature 293÷305 K, initial pressure 3÷18 bar and equivalence ratio = 1.0. The amount of H2 in the mixture was 0%, 20% and 30% (vol.). The effect of the initial pressure and of the Hydrogen content on the laminar burning velocity and the Markstein length has been evaluated: the relative weight and mutual interaction has been assessed of the two controlling parameters. Analysis has been carried out of the flame instability, expressed in terms of the critical radius for the onset of cellularity, as a function of the operating conditions.
Photo-Responsive Shape-Memory and Shape-Changing Liquid-Crystal Polymer Networks
Authors: Iqbal Danish , Samiullah Muhammad
Published: January 2013

“Surrounding matters” is a phrase that has become more significant in recent times when discussing polymeric materials. Although regular polymers do respond to external stimuli like softening of material at higher temperatures, that response is gradual and linear in nature. Smart polymers (SPs) or stimuli-responsive polymers (SRPs) behave differently to those external stimuli, as their behavior is more rapid and nonlinear in nature and even a small magnitude of external stimulus can cause noticeable changes in their shape, size, color or conductivity. Of these SRPs, two types of SPs with the ability to actively change can be differentiated: shape-memory polymers and shape-changing polymers. The uniqueness of these materials lies not only in the fast macroscopic changes occurring in their structure but also in that some of these shape changes are reversible. This paper presents a brief review of current progress in the area of light activated shape-memory polymers and shape-changing polymers and their possible field of applications.
Access to Any Site Directed Stable Isotope (2H, 13C, 15N, 17O and 18O) in Genetically Encoded Amino Acids
Authors: Dawadi Prativa , Lugtenburg Johan
Published: January 2013

Proteins and peptides play a preeminent role in the processes of living cells. The only way to study structure-function relationships of a protein at the atomic level without any perturbation is by using non-invasive isotope sensitive techniques with site-directed stable isotope incorporation at a predetermined amino acid residue in the protein chain. The method can be extended to study the protein chain tagged with stable isotope enriched amino acid residues at any position or combinations of positions in the system. In order to access these studies synthetic methods to prepare any possible isotopologue and isotopomer of the 22 genetically encoded amino acids have to be available. In this paper the synthetic schemes and the stable isotope enriched building blocks that are available via commercially available stable isotope enriched starting materials are described.
Stability of Recombinant Tissue Plasminogen Activator at −30 °C over One Year
Authors: Alkatheri Abdulmalik
Published: January 2013

Recombinant tissue plasminogen activator (rt-PA) is used to restore patency and avoid inadvertent removal of peripheral and central venous catheters. rt-PA was reconstituted (1 mg/mL) then cryopreserved at −30 °C for 1, 2, 3, 6, 8, and 12 months and, then its stability was determined. After cryopreservation for one and two months, rt-PA kept more than 95% of its activity compared to standard samples, while cryopreservation for three months caused 8% loss of activity. However, after cryopreservation for six months or more, rt-PA retained only 87.5% or less activity compared to standard samples. Therefore, it is recommended that reconstituted rt-PA be cryopreserved at −30 °C for a maximum period of three months.
Mid-Infrared Fiber-Coupled Photoacoustic Sensor for Biomedical Applications
Authors: Kottmann Jonas , Grob Urs , Rey Julien , Sigrist Markus
Published: January 2013

Biomedical devices employed in therapy, diagnostics and for self-monitoring often require a high degree of flexibility and compactness. Many near infrared (NIR) optical fiber-coupled systems meet these requirements and are employed on a daily basis. However, mid-infrared (MIR) fibers-based systems have not yet found their way to routine application in medicine. In this work we present the implementation of the first MIR fiber-coupled photoacoustic sensor for the investigation of condensed samples in the MIR fingerprint region. The light of an external-cavity quantum-cascade laser (1010–1095 cm-1) is delivered by a silver halide fiber, which is attached to the PA cell. The PA chamber is conically shaped to perfectly match the beam escaping the fiber and to minimize the cell volume. This results in a compact and handy sensor for investigations of biological samples and the monitoring of constituents both in vitro and in vivo. The performance of the fiber-coupled PA sensor is demonstrated by sensing glucose in aqueous solutions. These measurements yield a detection limit of 57 mg/dL (SNR = 1). Furthermore, the fiber-coupled sensor has been applied to record human skin spectra at different body sites to illustrate its flexibility.
Assessing Cycling Participation in Australia
Authors: Rissel Chris , Munro Cameron , Bauman Adrian
Published: January 2013

Planning and evaluating cycling programs at a national or state level requires accurate measures of cycling participation. However, recent reports of cycling participation have produced very different estimates. This paper examines the reported rates of cycling in five recent population surveys of cycling. Three surveys (one national and two from Sydney) asking respondents when they last rode a bicycle generated cycling participation (cycled in the past year) estimates of 29.7%, 34.1% and 28.9%. Two other national surveys which asked participants to recall (unprompted) any physical activity done for exercise, recreation or sport in the previous 12 months, estimated cycling in the past year as 11.1% and 6.5%. While unprompted recall of cycling as a type of physical activity generates lower estimates of cycling participation than specific recall questions, both assessment approaches produced similar patterns of cycling by age and sex with both approaches indicating fewer women and older adults cycling. The different question styles most likely explain the substantial discrepancies between the estimates of cycling participation. Some differences are to be expected due to sampling variability, question differences, and regional variation in cycling.
Fundamental Plant Biology Enabled by The Space Shuttle
Authors: Paul Anna‐Lisa , Wheeler Ray M. , Levine Howard G. , Ferl Robert J.
Published: January 2013

The relationship between fundamental plant biology and space biology was especially synergistic in the era of the Space Shuttle. While all terrestrial organisms are influenced by gravity, the impact of gravity as a tropic stimulus in plants has been a topic of formal study for more than a century. And while plants were parts of early space biology payloads, it was not until the advent of the Space Shuttle that the science of plant space biology enjoyed expansion that truly enabled controlled, fundamental experiments that removed gravity from the equation. The Space Shuttle presented a science platform that provided regular science flights with dedicated plant growth hardware and crew trained in inflight plant manipulations. Part of the impetus for plant biology experiments in space was the realization that plants could be important parts of bioregenerative life support on long missions, recycling water, air, and nutrients for the human crew. However, a large part of the impetus was that the Space Shuttle enabled fundamental plant science essentially in a microgravity environment. Experiments during the Space Shuttle era produced key science insights on biological adaptation to spaceflight and especially plant growth and tropisms. In this review, we present an overview of plant science in the Space Shuttle era with an emphasis on experiments dealing with fundamental plant growth in microgravity. This review discusses general conclusions from the study of plant spaceflight biology enabled by the Space Shuttle by providing historical context and reviews of select experiments that exemplify plant space biology science.
A proteomics approach identifies novel proteins involved in gravitropic signal transduction
Authors: Schenck Craig A. , Nadella Vijayanand , Clay Shannon L. , Lindner Jessica , Abrams Zachary , Wyatt Sarah E.
Published: January 2013

• Premise: Plant organs use gravity as a guide to direct their growth. And although gravitropism has been studied since the time of Darwin, the mechanisms of signal transduction, those that connect the biophysical stimulus perception and the biochemical events of the response, are still not understood.

• Methods: A quantitative proteomics approach was used to identify key proteins during the early events of gravitropism. Plants were subjected to a gravity persistent signal (GPS) treatment, and proteins were extracted from the inflorescence stem at early time points after stimulation. Proteins were labeled with isobaric tags for relative and absolute quantification (iTRAQ) reagents. Proteins were identified and quantified as a single step using tandem mass‐spectrometry (MS/MS). For two of the proteins identified, mutants with T‐DNA inserts in the corresponding genes were evaluated for gravitropic phenotypes.

• Key results: A total of 82 proteins showed significant differential quantification between treatment and controls. Proteins were categorized into functional groups based on gene ontology terms and filtered using groups thought to be involved in the signaling events of gravitropism. For two of the proteins selected, GSTF9 and HSP81‐2, knockout mutations resulted in defects in root skewing, waving, and curvature as well as in the GPS response of inflorescence stems.

• Conclusion: Combining a proteomics approach with the GPS response, 82 novel proteins were identified to be involved in the early events of gravitropic signal transduction. As early as 2 and 4 min after a gravistimulation, significant changes occur in protein abundance. The approach was validated through the analysis of mutants exhibiting altered gravitropic responses.
Amino-substituted diazocines as pincer-type photochromic switches
Authors: Sell Hanno , Näther Christian , Herges Rainer
Published: January 2013

Azobenzenes are robust, reliable, and easy to synthesize photochromic switches. However, their high conformational flexibility is a disadvantage in machine-like applications. The almost free rotation of the phenyl groups can be restricted by bridging two ortho positions with a CH2CH2 group, as realized in the dihydrodibenzo diazocine framework. We present the synthesis and properties of 3,3’-amino- and 3,3’-acetamido substituted diazocines. Upon irradiation with light of 405 and 530 nm they isomerize from the cis to the trans configuration and back, and thereby perform a pincer-like motion. In the thermodynamically more stable cis isomer the lone pairs of the amino nitrogen atoms point towards each other, and in the trans form they point in opposite directions. The distance between the amino nitrogen atoms changes between 8 Å (cis) and 11 Å (trans isomer).
SOME ASPECTS OF THE FORMATION OF PEDESTRIAN STREETS AND ZONES IN THE NEW PUBLIC SPACES OF URBAN CENTRE / MIESTO CENTRO NAUJŲ VIEŠŲJŲ ERDVIŲ – PĖSČIŲJŲ GATVIŲ IR ZONŲ – KŪRIMO KAI KURIE ASPEKTAI
Authors: Jakovlevas-Mateckis Konstantinas
Published: January 2013

Nowadays in urban centres, especially in old towns full of cars, the surroundings became noisy, polluted by gas, the beauty of architecture choked up, and a human being started feeling insecure and uncomfortable. This situation forces resolute actions to be taken. One of them – to oust cars from city centre and old town and form new public spaces there: pedestrian streets and even entire pedestrian zones. Therefore, this article examines evolution of formation of architectural environment of the pedestrian zones, their organization and realization abroad as well as our country's practical achievements and peculiarities. Spaces and their main components are examined in detail: the street size, greenery, small architecture and street design objects which form architectural environment. The main streets and pedestrian zones are presented in conclusions.

Santrauka

Šiandieninių miestų centruose, ypač senamiesčiuose, užtvindytuose automobilių, aplinka tapo triukšminga, oras užterštas, apstatymo architektūros grožis nustelbtas, o jų gyventojai ir lankytojai pasijuto nesaugiai ir diskomfortiškai. Ši situacija verčia imtis ryžtingų veiksmų. Vienas iš jų – išstumti automobilius iš miesto centro, senamiesčio branduolio ir kurti jame naujas viešąsias erdves: pėsčiųjų gatves ar net ištisas pėsčiųjų zonas. Todėl darbe nagrinėjami jų architektūrinės aplinkos formavimosi raida, organizavimo ir realizavimo užsienyje bei Lietuvoje praktikos pasiekimai ir ypatumai. Detaliau nagrinėjami pėsčiųjų gatvių ir pėsčiųjų zonų architektūrinę aplinką formuojančios erdvės ir pagrindinai jų komponentai: gatvės erdvės dydis, želdiniai, mažosios architektūros ir gatvės dizaino objektai. Išvadose pateikiami apibendrinimai: miesto pėsčiųjų gatvių ir pėsčiųjų zonų projektavimo pagrindiniai uždaviniai.
GREEN OPEN SPACE IN LARGE SCALE HOUSING ESTATES: A PLACE FOR CHALLENGE
Authors: Treija Sandra , Bratuškins Ugis , Bondars Edgars
Published: January 2013

The renewal of urban areas by developing green open spaces increases the overall quality of life and helps to reduce social exclusion. Urban green open space can help to constitute a framework where urban society and culture can develop, and to increase identity and a sense of community. It can be used to provide a ground for education and raise an awareness of the way ecosystems function and how urban functions can be integrated into the natural system. Despite the known socio-economic benefits resulting from it, considerations regarding sustainable land use planning often occupy a secondary role when designing city quarters. There exist many pressures – essentially market-related and driven by short-term thinking – for unsustainable development. Housing ownership reform, carrying out denationalization and privatization, along with a core capital for many inhabitants has also created a range of problems – one of them: as a result of denationalisation of land properties, when the land in large-scale residential districts was returned to the previous owners and then provided as the minimum required land to the privatised buildings, the original spatial composition of districts was completely destroyed, creating a legal basis for new construction in large-scale residential districts.
COMPARATIVE ANALYSIS OF METHODOLOGIES FOR LANDSCAPE ECOLOGICAL AESTHETICS IN URBAN PLANNING / KRAŠTOVAIZDŽIO EKOLOGINĖS ESTETINĖS URBANISTINIO PLANAVIMO METODOLOGIJOS PALYGINAMOJI ANALIZĖ
Authors: Jankevica Maija
Published: January 2013

Areas with high level of urbanisation provoke frequent conflicts between nature and people. There is a lack of cooperation between planners and nature scientists in urban studies and planning process. Landscapes usually are studied using the ecological and aesthetical approaches separately. However, the future of urban planning depends on integration of these two approaches. This research study looks into different methods of landscape ecological aesthetics and presents a combined method for urban areas. The methods of landscape visual aesthetical assessment, biotope structure analysis, landscape ecology evaluation and multi-disciplinary expert level are compared in the article. A comparison of obtained values is summarized by making a comparative matrix. As a result, a multi-stage model for landscape ecological aesthetics evaluation in urban territories is presented. This ecological aesthetics model can be successfully used for development of urban territories. Santrauka Aukštas teritorinės urbanizacijos lygis skatina dažną gamtos ir žmogaus konfliktą. Urbanistinio planavimo studijų procesuose trūksta bendradarbiavimo tarp urbanistinių teritorijų planavimo ir gamtos mokslo srityse dirbančių mokslininkų. Kraštovaizdis dažnai tyrinėjamas atskirai, taikant ekologinius ir estetinius metodus. Tačiau miestų planavimo ateitis priklauso nuo šių dviejų metodų integracijos. Šio tyrimo metu nagrinėjami skirtingi kraštovaizdžio ekologinės estetikos metodai ir pateikiamas apibendrintas urbanizuotoms teritorijoms skirtas sprendimas. Palyginti kraštovaizdžio vizualinio estetinio vertinimo, biotopų struktūros analizės, kraštovaizdžio ekologijos vertinimo metodai ir įvairių sričių ekspertų išvados. Gauti rezultatai suvesti į palyginamąją matricą. Viso to rezultatas – urbanistinių teritorijų daugiapakopis kraštovaizdžio ekologinės estetikos vertinimo modelis. Šis ekologinės estetikos modelis gali būti sėkmingai taikomas urbanistinių teritorijų plėtrai.
Landscape Ways Of Intervention Used In Reconversion Of Disused Old Defense Structures / INTERVENCIJOS Į KRAŠTOVAIZDĮ BŪDŲ NAUDOJIMAS SENOMS NEBENAUDOJAMOMS GYNYBOS STRUKTŪROMS PERTVARKYTI
Authors: Sorina-Georgiana Rusu
Published: January 2013

Because of the current world mutations, national security provides large complexity and requires new designing solutions for: security challenges, military technology, strategies and tactics, merging of structures, methods, techniques and technologies concerning security challenges, need for responding to social constraints (democratic rights, law of war), and attempts to surpass the opponent / enemy / partner, etc. So, in order to reconvert abandoned military areas, which were previously restricted (restricted areas) but currently passing transformation processes, we must consider the intervention both within and outside of a well-defined system. Therefore, we have to work inside and outside of the military system, as well as on the boundaries of hard-shaped structures. Camouflage is not only instructive for military practitioners’ intent on developing their skills, but also is interesting and entertaining means for much wider audience. Two case studies used as examples reveal the possibility that camouflage pattern concept may offer the effects that prove the chance of using camouflage as a scientific, designing and planning landscape tool. Results of the case studies indicate the importance and possibility of intervention integrated into the landscape by combining military means and elements of urban planning, and regulation specific to these types of functions.

Santrauka

Dėl pasaulyje vykstančių pokyčių rūpinimasis valstybės apsauga yra sudėtingas ir reikalauja naujų sprendimų ieškojimo, susijusių su saugumo iššūkiais, karinėmis technologijomis, strategijomis ir taktikomis, sujungiant struktūras, metodus, technikas ir technologijas, siejamas su saugumo problemomis, dėl būtinybės reaguoti į socialinius suvaržymus (demokratinės teisės, karo teisė), bandant pranokti priešininkus / partnerius ir t. t. Taigi, siekiant konvertuoti apleistas karines teritorijas, į kurias anksčiau patekti buvo draudžiama (draudžiamos teritorijos), vykstant kaitos procesams, reikia apsvarstyti intervenciją tiek gerai apibrėžtos sistemos viduje, tiek už jos ribų. Todėl karinės sistemos viduje ir už jos ribų reikia dirbti kaip griežtose struktūrose. Maskuotė naudojama ne tik karinių specialistų siekiui lavinti įgūdžius, bet ir kaip įdomi priemonė, skirta kur kas platesnei auditorijai. Dviejų atvejų tyrimai kaip pavyzdžiai atskleidžia galimybę, kad maskuotės modelio koncepcija gali išgauti poveikį, kuris įrodytų, jog maskuotę galima naudoti kaip mokslinį įrankį kraštovaizdžiui projektuoti ir planuoti.

Šio atvejo tyrimų rezultatai rodo integruotos į kraštovaizdį intervencijos svarbą ir galimybę derinti karines priemones, miestų planavimo elementus ir specifinį reguliavimą šio tipo funkcijoms.
HISTORIC GARDENS AND PARKS: CHALLENGES OF DEVELOPMENT IN THE CONTEXT OF RELEVANT REGULATIONS, DEFINITIONS AND TERMINOLOGY / ISTORINIAI SODAI IR PARKAI: VYSTYMOSI IŠŠŪKIAI REGLAMENTAVIMO, APIBRĖŽČIŲ IR TERMINIJOS KONTEKSTE
Authors: Dreija Kristīne
Published: January 2013

The title and contents of this article have emerged after trying to summarize international scientific knowledge and theory, regulations by relevant international organizations, as well as several national legislative provisions issued in the area of development of historical landscapes, environment and sites. Various definitions related to the subject, changing and newly introduced terminology have originally caused some embarrassment and provoked a series of questions, such as: who is who and what is the difference? In this respect, a historical garden or park as a significant area is defined as a ‘Living Monument’, ‘Tangible Heritage’ or even ‘Intangible Heritage’, because there is no doubt that the garden is a dynamic and ever changing environment. The applied terminology and definitions on historical gardens and parks are also undoubtedly related to the issues of heritage awareness. Differences in the national legislations are significant too, whereas historical gardens and parks are classified both, as architecture and natural monuments and heritage immovable property. An analysis at the theoretical level of the legislation and scientific statements provided in conclusion gives a certain insight into the significance of each projective aspect in the planning development of the historical gardens and parks and forms the base for further relevant issue researches. Santrauka Straipsnio pavadinimas ir turinys susiformavo apibendrinant mokslines žinias ir teoriją tarptautiniu mastu, tarptautinių organizacijų teisinį reglamentavimą, taip pat kelis nacionalinius teisės aktus, reguliuojančius istorinio kraštovaizdžio, aplinkos ar vietovės kaitą. Įvairūs susiję apibrėžimai, besikeičianti ir atnaujinama terminologija iš pradžių kelia sumišimą ir nemažai klausimų: kas yra kas ir kokie skirtumai? Šiuo atžvilgiu istorinis sodas ar parkas, kaip reikšminga teritorija, apibrėžiama kaip gyvas paminklas, materialusis paveldas ar net kaip nematerialusis paveldas, nes nėra abejonių, kad sodas yra dinamiška ir nuolat kintanti aplinka. Probleminė yra istoriniams sodams ir parkams taikoma terminija ir paveldo sampratos apibrėžimai. Akivaizdžių skirtumų esama valstybių teisės aktuose, kur istoriniai sodai ir parkai klasifikuojami kaip architektūros ar gamtos paminklai ar nekilnojama kultūros vertybė, atitinkamai skirtingai reglamentuojant. Teorinio teisės aktų ir mokslinės minties tyrimo apibendrinimas leidžia suvokti kiekvieno projektavimo aspekto svarbą istorinių sodų ir parkų plėtrai ir yra tolesnių aktualių tyrimų atspirtis.
SPATIAL, TEMPORAL AND SOCIAL DIMENSIONS OF THE LANDSCAPE INFLUENCED BY CONTEMPORARY ART / ŠIUOLAIKINIO MENO ĮTAKA KRAŠTOVAIZDŽIO ERDVINIAMS, LAIKO IR SOCIALINIAMS ASPEKTAMS
Authors: Alle Evita
Published: January 2013

The framework of this paper identifies various areas affected by the contemporary art practice in cultural landscape. Artistic practice in the landscape introduces new experiences to spectators. The author of this research explores what kinds of places are created by the contemporary art and whether it contributes to making new places. The research examines the identifying process of some features in creating the approach of dynamic landscape, and is carried out in accordance with the methodology of analysis. An approach of critical spatial practice proposed by Jane Rendell is explored through understanding the trialectical thinking. The research incorporates three parts: the spatial, temporal and social being for understanding nexus between an artwork and its settings. Expression means of artworks are analyzed in making the spatial analysis and clarifying the main features of connection. Among other indicators, cognition, place conception, context, refuge, connections, experience and temporality have been studied profoundly to understand the factors possibly influencing the landscape change. Santrauka Staipsnyje pateikiamos įvairios kultūrinį kraštovaizdį palietusios šiuolaikinio meno sritys. Stebint su kraštovaizdžiu susijusią meno praktiką, įgyjama naujos patirties. Darbo autorė tyrinėja šiuolaikinio meno įtaką erdvėms kurti. Tyrimo metu taikant analizės metodą nustatytos tam tikros kuriamo požiūrio į dinamišką kraštovaizdį ypatybės. Jane Rendell pasiūlyta kritinė erdvinė praktika nagrinėjama per trialektinio mąstymo suvokimą. Siekiant suprasti meno kūrinių ir aplinkos santykį, tyrimas buvo atliekamas susiejant erdvės, laiko ir socialinį aspektus. Meno kūrinių raiškos priemonės analizuotos erdvinės analizės būdu, nustatytos pagrindinės kūrinio ir jį supančios aplinkos ryšio savybės. Be kitų rodiklių – gebėjimo pažinti, vietos sampratos, situacijos, prieglobsčio, ryšių, patirties, laikinumo – buvo išsamiai nagrinėjami galimi kraštovaizdžio kaitos veiksniai.
MODELLING COLUMN BASES OF SEMI-RIGID STEEL FRAMES: STIFFNESS AND STRENGTH CALCULATION / PUSIAU STANDŽIŲ PLIENINIŲ RĖMŲ PĖDŲ MODELIAVIMAS, STANDŽIO IR STIPRIO NUSTATYMAS
Authors: Bučmys Žilvinas , Dališanskis Rimtautas
Published: January 2013

The paper examines the models and stiffness efficiency of the column base of semi-rigid steel frames, reviews stiffness calculation methods and calculates the rotation of column base connection in two ways: analytical, according to LST EN 1993-1-8, and finite element, applying nonlinear analysis. Two groups of modelling have been made: the first group deals with changes in the thickness of the base plate; the second one shows a different diameter of the anchor bolt. The obtained results reveal the influence of the base plate and anchor bolt on the stiffness of column base connection. The article discusses differences in the euro code and linear analysis: minimum difference makes 61,6% and maximum – 73,7%. For calculating the strength of the column base, a conservative model has been employed, i.e. according to the Eurocode, the received values are smaller compared to nonlinear analysis: minimum difference makes 37,0% and maximum – 49,0%.

Santrauka

Nagrinėjamas pusiau standžių plieninių rėmų pėdų modeliavimas ir standumo nustatymo efektyvumas. Apžvelgti kolonos pėdų standumo nustatymo metodai. Apskaičiuotas kolonos pėdos pasisukimas dviem būdais: pagal analitines išraiškas, kurios pateiktos LST EN 1993-1-8 dalyje, ir baigtinių elementų programą „Solid Works“ taikant netiesinę analizę. Sumodeliuotos dvi grupės: pirmojoje keičiamas pėdos pamatinės plokštės storis, o kitoje – inkarinio varžto skersmuo. Rezultatai rodo kolonos pėdos komponentų inkarinio varžto ir pamatinės plokštės įtaką bazės kampiniam posūkiui. Iš gautų rezultatų matyti, kad pagal Eurokodą ir netiesinę analizę kampiniai posūkiai skiriasi. Mažiausias skirtumas yra 61,6 %, o didžiausias – 73,7 %. Atliekant pėdos stiprumo skaičiavimus taikomas konservatyvus modelis – skaičiuojant pagal Eurokodą 3 gautos mažesnės reikšmės negu taikant netiesinę analizę. Mažiausias skirtumas yra 37,0 %, o didžiausias – 49,0 %.
THE IMPACT OF ADDITIVE ON THE PROPERTIES OF FRESH AND HARDENED MORTAR / PRIEDO POVEIKIS ŠVIEŽIO IR SUKIETĖJUSIO SKIEDINIO SAVYBĖMS
Authors: Šeputytė Jurga , Kičaitė Asta
Published: January 2013

This paper considers the impact of additives on the properties of mortar. For investigation purposes, two types of Portland cement (CEM II/A-LL 42.5 N and CEM I N (MA)), fine aggregate sand, lime, water and air-entraining and stabilizing additives were used. To determine the effects of additives on the mortar mix, the analysis of cone penetration into the mix, mortar mobility, water extraction out of mortar, density and flexural and compressive testing were conducted. When put into mortar, air-entraining and stabilizing additives changed structure. In this case, density and flexural and compressive strength of mortar are reduced. Santrauka Darbe nagrinėjamas priedo poveikis statybinio skiedinio savybėms. Tyrimams buvo naudojami dviejų rūšių portlandcementis (klinties portlandcementis CEM II/A-LL 42,5 N ir portlandcementis be mineralinių priedų CEM I 42,5 N), smulkusis užpildas smėlis, kalkės, vanduo ir priedas: orą įtraukiantis ir stabilizuojantis. Buvo atlikti šviežio skiedinio savybių tyrimai: kūgio įsmigimo į skiedinio mišinį, skiedinio pasklidimo, skiedinio mišinio vandens išsiskyrimo, šviežio skiedinio tankio ir sukietėjusio skiedinio lenkimo ir gniuždymo stiprumo tyrimai. Rezultatai parodė, kad daugiausia vandens reikia sunaudoti ruošiant skiedinius su portlandcemenčiu be priedo, o mažiausiai – su priedu. Paaiškėjo, kad skiedinių su mišriąja rišamąja medžiaga (portlandcementis su kalkių tešla) sklidumas yra didžiausias. Įdėjus priedo į skiedinį susidaro smulkios tolygiai pasiskirsčiusios poros ir sumažėja tankis. Tokiu atveju skiedinio bandinių lenkimo ir gniuždymo stipris yra mažesnis.