bluuebunny/crossref_metadata_2025 huggingface dataset:
An Evaluation of the Cross-Check Principle Using Visual Reinforcement Audiometry, Otoacoustic Emissions, and Tympanometry
Authors: Baldwin Stacey M. , Gajewski Byron J. , Widen Judith E.
Published: April 2011

Background:Early intervention to reduce the effects of congenital hearing loss requires accurate description of hearing loss. In pediatric audiology, a cross-check principle is used to compare behavioral and physiological tests.Purpose:The purpose of this study was to
investigate the correspondence of visual reinforcement audiometry (VRA) minimal response levels (MRLs), otoacoustic emissions (OAEs), tympanometry, and VRA test reliability to determine the odds of obtaining the expected cross-check results. We hypothesized that (1) when MRLs were within normal
limits (WNL), OAEs would be present; (2) in the event of normal MRLs and absent OAEs, tympanograms would be abnormal; and (3) in the event of elevated MRLs and present OAEs, the tester's confidence in the MRLs would be judged to be only fair, rather than good.Research Design:This was
a retrospective study.Study Sample:A previous study provided data from 993 infants who had diagnostic audiologic evaluations at 8‐12 mo of age.Data Collection and Analysis:The data were analyzed to compare VRA MRLs with OAE signal-to-noise ratios at 1, 2, and 4 kHz.
Odds ratios and 95% confidence intervals were calculated to test the three hypotheses related to the correspondence among MRLs, OAEs, tympanometry, and the reliability of MRLs.Results:The probability that OAEs would be present when MRLs were WNL varied from 12 to 26 to 1, depending
on the test frequency. When OAEs were absent in the presence of normal MRLs, the odds of abnormal tympanometry varied from 5 to 10 to 1, depending on the test frequency. When MRLs were elevated (>20 dB HL), the odds suggested that examiners judged the MRLs at 1 and 2 kHz to
lack reliability.Conclusion:The results suggest that the cross-check principle is effective when employing VRA, OAE, and tympanometry to rule out or determine the degree, type, and configuration of hearing loss in infants.
Partial Deafness Cochlear Implantation at the University of Kansas: Techniques and Outcomes
Authors: Prentiss Sandra , Sykes Kevin , Staecker Hinrich
Published: April 2011

Background:One of the most significant recent advances in cochlear implantation is the implantation of patients with residual hearing. These patients have a downsloping sensorineural hearing loss with poor speech discrimination and perform poorly with standard amplification.
Studies using a variety of different electrode designs have demonstrated that it is possible to implant an inner ear and preserve residual hearing. Initial studies have demonstrated that a combination of residual acoustic hearing in the low frequencies with electrical stimulation in the mid-
to high frequencies resulted in superior hearing performance in background noise.Purpose:The objective of this study was to determine the effect of electrode insertion depth on hearing preservation.Study Sample:Eighteen patients with mild to severe hearing loss in the low frequencies
combined with poor word recognition were recruited for the study.Intervention:Cochlear implantation.Data Collection and Analysis:Pre- and postoperative hearing test, Hearing in Noise Test, and consonant‐nucleus‐consonant testing. Data analysis was performed with
Kruskal Wallis and Mann-Whitney testing.Results:In our study of 18 patients implanted with a Med-El PulsarCI100 we demonstrated the ability to preserve residual hearing with implant insertion depths ranging from 20 to 28 mm, giving us the possibility of near complete cochlear
frequency coverage with an implant array while preserving residual hearing. These patients performed well both in quiet and in 10 dB signal-to-noise ratio conditions.Conclusion:Hearing preservation was achievable even with deep implant insertion. Patients performed well in combined
acoustic and electric conditions.
Does the Evidence Support Use of the Baha Implant System (Baha) in Patients with Congenital Unilateral Aural Atresia?
Authors: Danhauer Jeffrey L. , Johnson Carole E. , Mixon Melissa
Published: April 2011

Purpose:To determine if the evidence supports the recommendation of Baha implant systems (Bahas) over unaided conditions in persons with conductive hearing loss due to congenital unilateral aural atresia (CUAA), and if laboratory measures predict patient benefit and satisfaction.Research
Design:A systematic review.Methods:The authors constructed and submitted search strings to PubMed and other electronic databases to identify studies in peer-reviewed journals that were at an appropriate level of evidence (systematic reviews, randomized controlled trials, or nonrandomized
intervention studies); used outcome measures assessing audibility, localization, or speech-recognition in noise; included patients with CUAA using Bahas; and had intrepretable data. References of all retrieved articles were also hand searched for relevant studies. Evaluation forms were completed
by the authors for each of the included studies at all phases of the review including quality assessment and data extraction.Results:The authors reviewed 88 retrieved titles and excluded four that had no relevance to the topic and 67 that were duplicates. Abstracts were reviewed for
the remaining 17, and six nonrelevant studies were excluded. The remaining 11 articles were retrieved for full-text review; only three studies met inclusion criteria and were analyzed further. The three studies were not appropriate for a meta-analysis due to limited data, too few participants,
and insufficient presentations of results. Qualitative analysis revealed inconsistent findings across audiometric measures, and few significant differences were noted with and without Bahas, yet most participants believed that Bahas improved their quality of life. Laboratory measures did not
always predict patient benefit and satisfaction with Bahas.Conclusions:Results were limited for this narrow population having CUAA and the specific criteria used for this review. Audiologic measures generally failed to predict patients' success and/or satisfaction with their Bahas,
but most of the included studies showed that patients perceived some benefits. Ideally, clinical decision making should include the highest levels of scientific evidence. However, when evidence is unavailable or does not support a clear-cut recommendation for a particular treatment across
patients, as seems to be the case for the use of Bahas with CUAA, then clinicians must rely more heavily on clinical expertise and individual patient preferences in guiding clinical decision making.
Initial Development of a Spatially Separated Speech-in-Noise and Localization Training Program
Authors: Tyler Richard S. , Witt Shelley A. , Dunn Camille C. , Wang Wenjun
Published: April 2011

Objective:This article describes the initial development of a novel approach for training hearing-impaired listeners to improve their ability to understand speech in the presence of background noise and to also improve their ability to localize sounds.Design:Most people
with hearing loss, even those well fit with hearing devices, still experience significant problems understanding speech in noise. Prior research suggests that at least some subjects can experience improved speech understanding with training. However, all training systems that we are aware
of have one basic, critical limitation. They do not provide spatial separation of the speech and noise, therefore ignoring the potential benefits of training binaural hearing. In this paper we describe our initial experience with a home-based training system that includes spatially separated
speech-in-noise and localization training.Results:Throughout the development of this system patient input, training and preliminary pilot data from individuals with bilateral cochlear implants were utilized. Positive feedback from subjective reports indicated that some individuals were
engaged in the treatment, and formal testing showed benefit. Feedback and practical issues resulted from the reduction of an eight-loudspeaker to a two-loudspeaker system.Conclusions:These preliminary findings suggest we have successfully developed a viable spatial hearing training
system that can improve binaural hearing in noise and localization. Applications include, but are not limited to, hearing with hearing aids and cochlear implants.
Tinnitus Onset Rates from Chemotherapeutic Agents and Ototoxic Antibiotics: Results of a Large Prospective Study
Authors: Dille Marilyn F. , Konrad-Martin Dawn , Gallun Frederick , Helt Wendy J. , Gordon Jane S. , Reavis Kelly M. , Bratt Gene W. , Fausti Stephen A.
Published: April 2011

Background and Purpose:To report on the incidence and relative risk of tinnitus onset from a variety of drug therapies known to be ototoxic. Two main questions were asked: (1) What is the prevalence and incidence of tinnitus among patients treated with cisplatin, carboplatin,
or ototoxic antibiotic therapies? (2) Do commonly reported treatment or subject factors confound or modify the incidence of tinnitus onset?Data Collection and Analysis:A prospective observational study design was used to evaluate occurrence of significant otologic changes in 488 veterans
(962 ears) receiving chemotherapeutic agents (cisplatin, carboplatin), ototoxic antibiotics (primarily aminoglycoside), or nonototoxic drugs (control medications). A subset of 260 veterans lacking tinnitus prior to drug exposure was used to compare rates of tinnitus onset. Subjects were tested
prior to, during, and following their treatment. Planned comparisons using logistic regression, analysis of variance (ANOVA), and χ2 statistics were made among groups by the type of medication taken, age, presence of preexisting hearing loss, days on drug, and cumulative dose
of drug.Results:Baseline tinnitus rates were high (nearly 47%) relative to the general population of a similar age. Subjects with exposure to ototoxic medications had significantly increased risk for developing tinnitus. Those on chemotherapeutic agents were found to have the greatest
risk. Cisplatin elevated the risk by 5.53 times while carboplatin increased the risk by 3.75 over nonototoxic control medications. Ototoxic antibiotics resulted in borderline risk (2.81) for new tinnitus. Contrary to other reports, we did not find that subject factors (increased age or pre-existing
hearing loss) or treatment factors (days on drug or cumulative dose) contributed to rates of tinnitus onset during treatment.Conclusions:This large prospective study confirms that new tinnitus during treatment is associated with chemotherapy and with certain ototoxic antibiotic treatment.
Cisplatin and carboplatin were found to be the most potent ototoxic agents causing tinnitus at much greater numbers than the other drugs studied. Implications for counseling and audiological resource allocation are discussed.
Auditory Brain Stem Responses Evoked by Different Chirps Based on Different Delay Models
Authors: Cebulla Mario , Elberling Claus
Published: April 2011

Background:A cochlear delay model has previously been proposed for the construction of a chirp stimulus in order to compensate for the temporal dispersion in the auditory periphery. The large intersubject variability in the model data suggests that a chirp constructed from the
average model data will not be able to compensate equally well for the temporal dispersion in all normal-hearing subjects. For the recording of the auditory brain stem response (ABR), it has been suggested that the most efficient chirp for generating the largest response amplitude changes
in duration with level, indicating that the delay model exhibits a latency change with frequency, which becomes larger at lower levels.Purpose:To investigate in normal-hearing subjects how the ABR varies in response to five different chirps and to study how the efficiency of each chirp
changes with stimulus level.Research Design:A click and five chirps of different durations and constructed from the proposed delay model were designed with identical amplitude spectra. The six stimuli were used to record the ABR from 50 normal-hearing test subjects using a quasi-simultaneous
stimulation technique at 50 and 30 dB nHL. The ABR recordings were evaluated by the peak-to-trough amplitude and the peak latency.Results:For the test group the following level effect was demonstrated: at 50 dB nHL the largest response amplitude was provided by a shorter chirp,
whereas at 30 dB nHL the largest response amplitude was provided by a longer chirp. There is, however, large variability as to which of the five chirps generated the largest response in each individual subject, but at the two levels of stimulation, the best chirps were significantly correlated
across the test group. All five chirps generated significantly larger ABRs than the click, but at 30 dB nHL the gain in response amplitude by using the chirps instead of the click was larger than at 50 dB nHL.Conclusions:A chirp that evokes the largest broadband ABRs in normal-hearing
subjects changes in duration with level—that is, being relatively short at higher levels (50 dB nHL) and relatively long at lower levels and near the threshold. However, the changes in amplitude in response to chirps of different durations are not very large, and it is therefore
uncertain whether the outcome from using such chirps actually would outweigh the instrumental complexity of implementation. It appears that the largest advantage of using the chirp over the click is found at the lower levels of stimulation.
Sound Localization Acuity in Children with Unilateral Hearing Loss Who Wear a Hearing Aid in the Impaired Ear
Authors: Johnstone Patti M. , Náblek Anna K. , Robertson Velma S.
Published: April 2011

Background:Disrupted binaural hearing is thought to contribute in part to the academic, social, and communication problems often associated with unilateral hearing loss (UHL) in childhood. It is not known, however, if putting a hearing aid in the impaired ear of a child with
UHL will lead to bilateral or binaural benefit. This study seeks to utilize sound localization acuity measurements to assess hearing aid amplification efficacy in children with UHL.Purpose:To measure sound localization ability in children with UHL who use a hearing aid in the impaired
ear to determine the extent to which amplification, age, early intervention, and degree of hearing loss affects localization acuity.Research Design:A within-subjects experimental design using repeated measures is used to determine the effect of amplification on localization acuity in
children with UHL. A between-subjects experimental design is used to compare localization acuity between children with UHL and age-matched controls with normal hearing.Study Sample:Twelve children with UHL who used a hearing aid in the impaired ear and 12 age-matched controls with normal
hearing. Children with UHL were divided into two groups based on degree of hearing loss. Children in both groups were divided into two age groups: older children (10‐14 yr) and younger children (6‐9 yr).Data Collection and Analysis:All testing was done in
a sound-treated booth with a horizontal array of 15 loudspeakers (radius of 1 m). The stimulus was a spondee word, “baseball”: the level averaged 60 dB SPL and randomly roved (±8 dB). Each child was asked to identify the location of a sound source.Results:In
the experimental study a significant interaction was found between hearing aid amplification and child age. A hearing aid significantly improved localization acuity in younger children with UHL and significantly impaired localization acuity in older children. A significant correlation was
found between age at intervention and localization bilateral benefit. Children who were fit earlier showed bilateral benefit whereas children who were fit later showed bilateral interference. Development, however, may play a role in sound localization acuity. When unaided, older children had
significantly better localization acuity than younger children with UHL.Conclusions:A hearing aid can provide bilateral localization benefit to some children with UHL. Early intervention may increase the likelihood of bilateral benefit. However, developmental factors appear to play
a role in improving localization abilities over time for children with UHL. Nonetheless, without a means of establishing bilateral benefit with hearing aid amplification, localization performance in children with UHL will rarely equal that of peers.
Multiple-ASSR Thresholds in Infants and Young Children with Hearing Loss
Authors: Van Maanen Anna , Stapells David R.
Published: April 2011

Background:The multiple auditory steady-state response (multiple ASSR) is a promising technique for determining thresholds for infants and children. However, there are few data for infants and young children with hearing loss where multiple-ASSR thresholds have been compared
to frequency-specific gold standard (i.e., behavioral or tone-evoked auditory brainstem response [tone ABR]) measures.Purpose:The study compared multiple-ASSR and tone-ABR thresholds and assessed how well “normal” ASSR levels differentiate normal from elevated thresholds.Research
Design:Multiple-ASSR and tone-ABR results (to air-conduction stimuli) were obtained in infants and young children with hearing loss or normal hearing.Study Sample:98 infants with hearing loss (53 infants provided thresholds) and 34 infants with normal hearing.Data Collection
and Analysis:Multiple-ASSR and tone-ABR results were typically completed on the same day. Correlations between ASSR and ABR thresholds, linear regressions, and ASSR-minus-ABR threshold difference scores were calculated for each group (normal or hearing loss), and for both groups combined.Results:Multiple-ASSR
thresholds (dB HL) were strongly correlated (r = .97) with tone-ABR thresholds (dB nHL) for 500, 1000, 2000, and 4000 Hz. Mean (±1 SD) difference scores (ASSR-minus-ABR) were 10.7 ± 9.0, 9.5 ± 9.4, 9.2 ± 9.0, and 6.3 ± 9.5 dB for 500,
1000, 2000, and 4000 Hz, respectively. The previously published “normal” ASSR levels accurately differentiated normal from elevated thresholds. Out of 523 tests with elevated tone-ABR thresholds, the multiple ASSR was “normal” in only 22 tests. In these 13 infants,
other ASSR frequencies were elevated, and thus the infants would not have “passed” the ASSR.Conclusions:There are few studies of infants and young children comparing ASSR thresholds to frequency-specific gold standard measures, especially using the multiple-ASSR technique.
The present study, comparing multiple-ASSR to tone-ABR thresholds, nearly doubles the multiple-ASSR sample size in the literature. The results indicate that the multiple-ASSR and tone-ABR thresholds are strongly correlated, and the “normal” multiple-ASSR levels of 50, 45, 40, and
40 dB HL correctly classified children as having “normal” or “elevated” thresholds. However, due to the lack of air- and bone-conduction data in infants with different types and degrees of hearing loss, further ASSR research is needed.
Sensory-Cognitive Interaction in the Neural Encoding of Speech in Noise: A Review
Authors: Anderson Samira , Kraus Nina
Published: April 2011

Background:Speech-in-noise (SIN) perception is one of the most complex tasks faced by listeners on a daily basis. Although listening in noise presents challenges for all listeners, background noise inordinately affects speech perception in older adults and in children with learning
disabilities. Hearing thresholds are an important factor in SIN perception, but they are not the only factor. For successful comprehension, the listener must perceive and attend to relevant speech features, such as the pitch, timing, and timbre of the target speaker's voice. Here, we review
recent studies linking SIN and brainstem processing of speech sounds.Purpose:To review recent work that has examined the ability of the auditory brainstem response to complex sounds (cABR), which reflects the nervous system's transcription of pitch, timing, and timbre, to be used as
an objective neural index for hearing-in-noise abilities.Study Sample:We examined speech-evoked brainstem responses in a variety of populations, including children who are typically developing, children with language-based learning impairment, young adults, older adults, and auditory
experts (i.e., musicians).Data Collection and Analysis:In a number of studies, we recorded brainstem responses in quiet and babble noise conditions to the speech syllable /da/ in all age groups, as well as in a variable condition in children in which /da/ was presented in the context
of seven other speech sounds. We also measured speech-in-noise perception using the Hearing-in-Noise Test (HINT) and the Quick Speech-in-Noise Test (QuickSIN).Results:Children and adults with poor SIN perception have deficits in the subcortical spectrotemporal representation of speech,
including low-frequency spectral magnitudes and the timing of transient response peaks. Furthermore, auditory expertise, as engendered by musical training, provides both behavioral and neural advantages for processing speech in noise.Conclusions:These results have implications for future
assessment and management strategies for young and old populations whose primary complaint is difficulty hearing in background noise. The cABR provides a clinically applicable metric for objective assessment of individuals with SIN deficits, for determination of the biologic nature of disorders
affecting SIN perception, for evaluation of appropriate hearing aid algorithms, and for monitoring the efficacy of auditory remediation and training.
Adapting to Changed Hearing: The Potential Role of Formal Training
Authors: Boothroyd Arthur
Published: April 2011

Changed hearing occurs when sensorineural loss is acquired or increases, when hearing aids or cochlear implants are first acquired, when hearing aids are reprogrammed, and when cochlear implants are remapped. The changes affect speech perception—a process in which decisions about
a talker's language output are made on the basis of sensory and contextual evidence, using knowledge and skill. The importance of spoken communication dictates speedy and optimal adaptation to changed hearing. Adaptation is a process in which the individual acquires new knowledge and modifies
skill. Formal training provides the listener with the opportunity to enhance both knowledge and skill by spending time on speech perception tasks without the demands, constraints, uncertainties, and risks associated with everyday communication. Benefits of such training have been demonstrated
in terms of improvement on trained tasks and talkers, generalization to untrained tasks and talkers, improvements in self-perceived competence, and reduction of self-perceived handicap. So far, however, we lack information on which aspects of training are responsible for benefit, which aspects
of perception are changed, how individual differences interact with the foregoing, and whether these benefits translate into significantly increased participation and quality of life.
Some Observations on the Nature of the Audiometric 4000 Hz Notch: Data from 3430 Veterans
Authors: Wilson Richard H.
Published: April 2011

Background:Pure-tone, air-conduction audiograms notched at 4000 Hz have long been considered the signature configuration for noise-induced hearing loss even though there is an extensive literature that does not mesh with this simple explanation. There are many reports of
notched audiograms from individuals with no history of noise exposure and, conversely, reports of audiograms with no notches from individuals with a history of noise exposure. Recent reports increasingly suggest that unilateral 4000 Hz notches are common. The prevalence of notched audiograms
at 4000 Hz is dependent on the definition of the notch and the population under study.Purpose:To examine the prevalence and characteristics of audiograms that are notched at 4000 Hz.Research Design:Retrospective, descriptive.Study Sample:The participants were
3430 veterans evaluated in the Audiology Clinic at the VA Medical Center, Mountain Home, Tennessee. The mean age was 62.3 yr.Data Collection and Analyses:The data were collected in the course of a 60 min, routine audiological evaluation. In addition to pure-tone audiometry,
a history, otoscopy, speech audiometry in quiet and in noise, and aural-acoustic immittance measures were included in the clinic protocol but were not evaluated in this report. A notch was defined when the 4000 Hz threshold minus the 2000 Hz threshold and the 4000 Hz threshold
minus the 8000 Hz threshold both were ≥10 dB.Results:Overall the mean LE (left ear) thresholds at 2000, 3000, and 4000 Hz were at hearing levels 2‐3 dB higher than the hearing levels for the corresponding mean RE (right ear) thresholds; the differences
were significant. A notched audiogram was observed in 40.6% of the participants in at least one ear with 15.4% having bilateral notches, 28.8% LE notches, and 27.1% RE notches. Unilateral 4000 Hz notches were almost twice as prevalent as bilateral 4000 Hz notches. Viewed as a function
of age, notched audiograms were most common (∼35% of the participants) in the 40 and 50 yr groups with a diminishing prevalence in the 60‐80 yr groups. The mean notch depth at 4000 Hz was consistently 20‐26 dB across the seven age groups. In comparison
to the thresholds of the audiograms that were not notched, the thresholds of the audiograms with 4000 Hz notches (1) at 250‐2000 Hz were at hearing levels 2‐3 dB lower, (2) at 3000 and 4000 Hz were at hearing levels 8‐17 dB higher, and (3) at 8000 Hz
were at hearing levels 3‐4 dB lower; the threshold differences were significant at all frequencies for both ears.Conclusions:The data suggest that unilateral, 4000 Hz notched audiograms are as common or more common than bilateral notched audiograms and that unilateral
notched audiograms are equally common for the LE and RE. The prevalence and characteristics of 4000 Hz notched audiograms in this veteran sample are similar to those observed in the population as a whole.
Abiotic Stress‐Related Expressed Sequence Tags from the Diploid Strawberry Fragaria vesca f. semperflorens
Authors: Rivarola Maximo , Chan Agnes P. , Liebke David E. , Melake‐Berhan Admasu , Quan Hui , Cheung Foo , Ouyang Shu , Folta Kevin M. , Slovin Janet P. , Rabinowicz Pablo D.
Published: April 2011

Strawberry (Fragaria spp.) is a eudicotyledonous plant that belongs to the Rosaceae family, which includes other agronomically important plants such as raspberry (Rubus idaeus L.) and several tree‐fruit species. Despite the vital role played by cultivated strawberry in agriculture, few stress‐related gene expression characterizations of this crop are available. To increase the diversity of available Fragaria transcriptome sequence, we produced 41,430 Fragaria vesca L. expressed sequence tags (ESTs) from plants growing under water‐, temperature‐, and osmotic‐stress conditions as well as a combination of heat and osmotic stresses that is often found in irrigated fields. Clustering and assembling of the ESTs resulted in a total of 11,836 contigs and singletons that were annotated using Gene Ontology (GO) terms. Furthermore, over 1200 sequences with no match to available Rosaceae ESTs were found, including six that were assigned the “response to stress” GO category. Analysis of EST frequency provided an estimate of steady state transcript levels, with 91 sequences exhibiting at least a 20‐fold difference between treatments. This EST collection represents a useful resource to advance our understanding of the abiotic stress‐response mechanisms in strawberry. The sequence information may be translated to valuable tree crops in the Rosaceae family, where whole‐plant treatments are not as simple or practical.
Density Stress has Minimal Impacts on the Barley or Maize Seedling Transcriptome
Authors: St. Pierre Summer , Springer Nathan M. , Muehlbauer Gary J.
Published: April 2011

High planting density affects the morphology and productivity of many crop species. Our objectives were to examine the phenotypic and transcriptomic changes that occur during plant density stress in barley (Hordeum vulgare L.) and maize (Zea mays L.) seedlings. In maize and barley seedlings, density stress impacted several morphological traits. Gene expression profiles were examined in four barley and five maize genotypes grown at low and high plant densities. Only 221 barley and 35 maize genes exhibited differential expression in response to plant density stress. The majority of the gene expression changes were observed in a subset of the genotypes and reflected minor changes in the level of expression, indicating that the plant density stress imposed in this study did not result in major changes in gene expression. Also, little overlap was observed within barley or maize genotypes in gene expression during density stress, indicating that genotypic differences play a major role in the response to density stress. While it is clear that gene expression differences are involved in morphological changes induced by high plant densities, it is likely that many of these gene expression differences are subtle and restricted to particular tissues and developmental time.
Development, Characterization, and Linkage Mapping of Single Nucleotide Polymorphisms in the Grain Amaranths (Amaranthus sp.)
Authors: Maughan P.J. , Smith S.M. , Fairbanks D.J. , Jellen E.N.
Published: April 2011

The grain amaranths (Amaranthus sp.) are important pseudo‐cereals native to the New World. During the last decade they have garnered increased international attention for their nutritional quality, tolerance to abiotic stress, and importance as a symbol of indigenous cultures. We describe the development of the first single nucleotide polymorphism (SNP) assays for amaranth. In addition, we report the characterization of the first complete genetic linkage map in the genus. The SNP assays are based on KASPar genotyping chemistry and were detected using the Fluidigm dynamic array platform. A diversity screen of 41 accessions of the cultivated amaranth species and their putative ancestor species (Amaranth hybridus L.) showed that the minor allele frequency (MAF) of these markers ranged from 0.05 to 0.5 with an average MAF of 0.27 per SNP locus. One hundred and forty‐one of the SNP loci were considered highly polymorphic (MAF ≥ 0.3). Linkage mapping placed all 411 markers into 16 linkage groups, presumably corresponding to each of the 16 amaranth haploid chromosomes. The map spans 1288 cM with an average marker density of 3.1 cM per marker. The work reported here represents the initial first steps toward the genetic dissection of agronomically important characteristics in amaranth.
DYNAMIC TEMPERATURE SIMULATION IN DISTRICT HEATING SYSTEMS IN DENMARK REGARDING PRONOUNCED TRANSIENT BEHAVIOUR / DANIJOS ŠILUMOS TIEKIMO SISTEMŲ MODELIAVIMAS, ĮVERTINANT NESTACIONARŲ TEMPERATŪROS PASISKIRSTYMĄ TINKLE
Authors: Gabrielaitienė Irena , Bøhm Benny , Sundén Bengt
Published: April 2011

A dynamic performance of district heating systems was analysed with an emphasis on temperature profile distortion throughout a heating system network. Therefore, a modelling approach (the so-called node method) developed at the Technical University of Denmark was applied. For comparison purposes, commercial TERMIS software was also used in this work. Typical supply conditions were investigated in the considered district heating systems in Denmark. Large and sudden temperature changes in supply temperature were depicted in the district heating system in Madumvej while the pronounced transient supply conditions of temperature wave were exhibited in the district heating system in Naestved. Time-dependent consumer data from the district heating systems were applied to compare the results obtained from modelling approaches. Based on the analysis of temperature wave propagation through the network, it was noted that temperature wave spread unevenly on different locations of the network.

Santrauka

Nestacionarus šilumos sistemos darbas buvo analizuojamas atsižvelgiant į palyginti didelius ir staigius šilumnešio temperatūros pokyčius šilumos šaltinyje. Nestacionarūs vartotojų duomenys iš dviejų Danijos šilumos tiekimo sistemų buvo įvertinti ir pritaikyti modeliuojant šilumos tiekimo tinklus. Esant nestacionariam būviui, kuris atsiranda dėl kintamų vartotojų poreikių, svarbu įvertinti sistemos inertiškumą. Dėl to pailgėja laikas, per kurį pakitęs šilumnešio būvis pasiekia vartotoją. Siekiant nustatyti, ar vartotojų poreikiai bus tenkinami, nestacionarus temperatūros pasiskirstymas tinkle buvo apskaičiuotas taikant mazgų metodą (angl. the node method) ir TERMIS programinę įrangą. Šilumnešio parametrai ir sistemos inertiškumas buvo įvertinti modeliuojant dvi Danijos šilumos tiekimo sistemas. Gauti temperatūros pasiskirstymo tinkle rezultatai buvo palyginti su eksperimentiniais duomenimis.
LABORATORY FATIGUE MODELS FOR RECYCLED MIXES WITH POZZOLANIC CEMENT AND BITUMEN EMULSION / PUCOLANINIO CEMENTO IR BITUMINIŲ EMULSIJŲ MIŠINIŲ PERDIRBIMO LABORATORINIAI NUOVARGIO MODELIAI
Authors: Kavussi Amir , Nejad Fereidoon Moghadas , Modarres Amir
Published: April 2011

In recent years, due to technical and economical advantages, the production of pozzolanic cements have considerably extended. In the case of asphalt recycling, using Pozzolonic cements has several advantages. Lower initial stiffness and less shrinkage microcracks than Ordinary Portland Cement (OPC) are some benefits of pozzolanic cements which may reduce the probability of occuring premature cracking in recycled layer. In this reserach in order to investigate the effects of I (PM) pozzolanic cement on the fatigue cracking of recycled mixes with bitumen emulsion and develope fatigue models for these mixes, extensive indirect tensile fatigue and resilient modulus tests were performed at different temperatures and curing times. Test results showed that at high strain levels I (PM) cement specimens have superior fatigue behavior than OPC specimens. Furthermore, the effects of I (PM) cement on fatigue life of recycled mixes related to the initial strain level. Therefore a boundary strain level was determined. Above the boundary strain level, adding cement caused a reduction in fatigue life, whereas below that level the reverse was true. Finally based on laboratory testing results distinct models were established for different boundary strain levels. Santrauka Pastaraisiais metais dėl techninių ir ekonominių veiksnių pucolaninio cemento gamyba gerokai padidėjo. Pucolaninio cemento naudojimas perdirbant asfaltą turi keletą pranašumų. Mažesnis pradinis standumas ir mažiau mikroįtrūkių nei įprastame portlandcementyje (Ordinary Portland Cement, OPC) – tai keletas pucolaninio cemento pranašumų, galinčių sumažinti priešlaikinio plyšių atsiradimo tikimybę perdirbamame sluoksnyje. Šiuo moksliniu tyrimu siekiama ištirti I (PM) pucolaninio cemento poveikį nuovargio plyšių atsiradimui perdirbamuose bituminių emulsijų mišiniuose ir sukurti šių mišinių nuovargio modelius. Buvo atlikti išplėstiniai netiesioginio tempimo nuovargio ir elastingumo modulių bandymai, esant skirtingoms temperatūroms ir džiūvimo laikui. Bandymų rezultatai parodė, kad esant aukštam įtempimo lygiui I(PM) cemento bandiniai yra atsparesni nuovargiui nei portlandcemenčio (Ordinary Portland Cement, OPC) bandiniai. Be to, perdirbtų mišinių iš I (PM) cemento tvarumas yra artimas pirminiam įtempimo lygiui. Todėl buvo nustatytas ribinis įtempimo lygis. Viršijus ribinį įtempimo lygį ir įmaišius cemento tvarumas sumažėja, o esant žemesniam įtempimo lygiui buvo gautas priešingas rezultatas. Galiausiai remiantis tyrimais buvo nustatyti atskiri modeliai skirtingiems ribiniams įtempimo lygiams.
METHOD OF PREDICTION OF THERMAL CONDUCTIVITY COEFFICIENT OF WALL MATERIALS CONTAINING SALTS / SIENŲ DRUSKINGŲ MEDŽIAGŲ ŠILUMOS LAIDUMO KOEFICIENTO PROGNOZĖS METODAS
Authors: Kosior-Kazberuk Marta , Ezerskiy Valeriy
Published: April 2011

The salt presence in porous structure of wall materials causes changes in thermal conductivity. The real value of material thermal conductivity in service conditions is necessary for engineering applications. The method of prediction of the thermal conductivity coefficient for wall materials containing salt using corrective factor is presented in the paper. By means of corrective coefficients, for well-known content of moisture and salt in wall material, it is possible to calculate thermal conductivity coefficient with regard to the presence of specific salt or mix of salts in material. The corrective coefficient values were determined for different groups of salts. The partition of salts into groups was made by means of cluster analysis, in dependence on their influence on material thermal conductivity. Clustering, in data mining, is a useful tool for discovering groups and identifying interesting distributions in the underlying data. Santrauka Druskos poringųjų medžiagų sienų struktūroje sukelia jų šilumos laidumo kitimą. Tikroji eksploatacinė medžiagų šilumos laidumo koeficiento vertė būtina atliekant inžinerinius tyrimus. Straipsnyje pristatomas sienų, kurių medžiagos turi druskų, šilumos laidumo koeficiento prognozės metodas naudojant pataisos daugiklį. Naudojant pataisos koeficientus, esant tiksliai žinomam drėgmės ir druskų kiekiui sienos medžiagoje, galima apskaičiuoti šilumos laidumo koeficientą, atsižvelgus į tam tikrų druskų ar jų mišinių buvimą medžiagoje. Buvo nustatytos įvairių druskų grupių pataisos koeficientų vertės. Druskos buvo paskirstytos grupėmis pagal klasterinę analizę, priklausomai nuo jų įtakos medžiagos šilumos laidumui. Klasterių metodas yra naudinga priemonė duomenims apdoroti—grupėms atskleisti ir įdomiems duomenų pasiskirstymams rasti.
THE DEPENDENCE OF THE VALUE OF CERAMICS RESISTANCE TO FROST ON THE COMPOSITION OF RAW MATERIAL MIXTURE / KERAMIKOS ATSPARUMO ŠALČIUI PRIKLAUSOMYBĖ NUO FORMAVIMO MIŠINIO SUDĖTIES
Authors: Mačiulaitis Romualdas , Malaiškienė Jurgita
Published: April 2011

The operational resistance of ceramic products to frost is a persistent problem. In order such products should remain of high quality without losing their initial qualities for a long time, it is necessary to improve the technological process of production. This work is confined to selecting the composition of the formation mix in order to turn attention to the amount of every component of the formation mix that can positively or negatively influence the operational resistance of ceramics to frost. The paper presents 8 formed batches of ceramic samples different in composition while being dried and burned under similar conditions. Operational resistance to frost was determined according to the established standard. The performed analysis of the obtained experimental data allowed working out an empirical equation forecasting operational resistance to frost according to the composition of the formation mix. Santrauka Keraminių gaminių eksploatacinis atsparumas šalčiui yra svarbi šių dienų problema. Kad keraminiai mūro gaminiai ilgai išliktų kokybiški, nepraradę savo pradinių savybių, reikia tobulinti technologinį jų gamybos procesą. Šiame darbe buvo nustatyta, kaip kiekvienas formavimo mišinio komponento kiekis gali lemti keraminių bandinių eksploatacinį atsparumą šalčiui. Atliekant darbą, buvo suformuotos aštuonios keraminių bandinių partijos. Jos buvo sudarytos iš tokių formavimo mišinio komponentų, kaip molis, smėlis, maltas stiklas, skaldelė, durpės ir antracitas. Bandiniai buvo džiovinami ir degami vienodomis sąlygomis (didžiausia degimo temperatūra—1080°C). Eksploatacinis atsparumas šalčiui buvo nustatytas pagal tuo metu galiojusio LST 1272–92 standarto 3.5.3 p. Atlikus regresinę gautų eksperimentinių duomenų analizę, buvo sudaryta empirinė lygtis, kuria remiantis galima prognozuoti eksploatacinį atsparumą šalčiui pagal formavimo mišinio sudėtį.
MATHEMATICAL MODELLING OF DISPUTE PROCEEDINGS BETWEEN INVESTORS AND THIRD PARTIES ON ALLEGEDLY VIOLATED THIRD-PARTY RIGHTS / GINČO PROCESO TARP INVESTUOTOJŲ IR TREČIEJŲ ASMENŲ DĖL GALIMAI PAŽEISTŲ TREČIEJŲ ASMENŲ TEISIŲ MATEMATINIS MODELIAVIMAS
Authors: Šostak Olga Regina , Vakrinienė Sigutė
Published: April 2011

The article analyses the possible influence of third-party rights infringed during construction planning on the implementation of an investment project. In a construction project, judicial disputes are an unwanted risk factor, which may disrupt the entire project. It is therefore necessary to plan and apply preventive measures for the mitigation of such risk in the initial planning stage of a construction project. The article, for that purpose, presents modelling a dispute between investors and third persons on allegedly violated third-party rights with the help of a tree that illustrates the possible actions of the dispute parties. A mathematical model for dynamic programming the dispute on allegedly violated third-party rights has been developed; it helps to determine the optimal investor's strategies for each situation that involves decision-making. Santrauka Nagrinėjama, kaip trečiųjų asmenų teisių pažeidimai, planuojant statybas, gali veikti investicinio projekto įgyvendinimą. Įgyvendinant statybos projektą, teisminio ginčo atsiradimas yra nepageidaujamas rizikos faktorius, galintis sužlugdyti visą projektą. Todėl vykdant statybos projektą jau pradiniame projekto planavimo etape būtina numatyti ir taikyti prevencines priemones tokios rizikos mažinimui. Siekiant šio tikslo straipsnyje atliktas ginčo tarp investuotojų ir trečiųjų asmenų dėl galbūt pažeistų trečiųjų asmenų teisių modeliavimas, sudarant ginčo šalių elgsenos variantų formavimo medį. Sudarytas ginčo proceso dėl galbūt pažeistų trečiųjų asmenų teisių dinaminio programavimo matematinis modelis, leidžiantis nustatyti optimalias investuotojo strategijas kiekvienoje situacijoje, kai reikia priimti sprendimus.
A MODEL FOR STRENGTH AND STRAIN ANALYSIS OF STEEL FIBER REINFORCED CONCRETE / BETONO, ARMUOTO PLIENINE DISPERSINE ARMATURA, STIPRIO IR DEFORMACIJU APSKAICIAVIMO MODELIS
Authors: Marciukaitis Gediminas , Šalna Remigijus , Jonaitis Bronius , Valivonis Juozas
Published: April 2011

The article proposes a model for strength and stain analysis of steel fiber reinforced concrete (SFRC). The model is based on general principles for creating and modelling structural composites and on reinforced concrete code. Differently from other examples, the elastic and plastic properties of the components (concrete and steel) of the introduced model are directly taken into account. The model gives an opportunity to determine tension and compression strength, the elasticity modulus of fiber concrete and the main parameters of its elasticity and plasticity. A good agreement between the obtained results and those of experiments performed by other investigators was confirmed. Differences between the ratios of theoretical and experimental values are insignificant and vary within the limits of 1.06–1.10. This model may be used for the analysis of reinforced concrete members reinforced by steel fibers (SFRC) in a dispersible way assuming stress distribution diagrams. Santrauka Straipsnyje pasiulytas betono, armuoto plienine dispersine armatura, stiprio ir deformaciju skaiciavimo modelis, pagristas bendraisiais statybiniu kompozitu kurimo ir modeliavimo principais bei gelžbetonio normomis. Šiame modelyje skirtingai nuo daugelio kitu yra tiesiogiai ivertinamos tampriosios ir plastinės kompozito komponentu (betono ir plieninės dispersinės armaturos) savybės. Modelis leidžia apskaiciuoti betono, armuoto plienine dispersine armatura, tempiamaji ir gniuždomaji stiprius, tamprumo moduli ir pagrindinius jo deformatyvumo parametrus—tamprumo ir plastiškumo koeficientus. Siulomo modelio palyginimas su šio straipsnio ir kitu autoriu atliktais eksperimentu duomenimis parodė, kad rezultatai sutampa. Teoriniu ir eksperimentiniu reikšmiu santykiai skiriasi nedaug ir kinta nuo 1,06 iki 1,10. Šis modelis gali buti taikomas priimant itempiu pasiskirstymo diagramas apskaiciuojant lenkiamuosius, plienine dispersine armatura armuotus betoninius elementus.
THE LONG-RUN RELATIONSHIP BETWEEN THE CONSTRUCTION SECTOR AND THE NATIONAL ECONOMY IN CAPE VERDE / ILGALAIKIAI RYŠIAI TARP STATYBOS SEKTORIAUS IR NACIONALINĖS EKONOMIKOS ŽALIAJAME KYŠULYJE
Authors: Lopes Jorge , Nunes Alcina , Balsa Carlos
Published: April 2011

The relationship between a country's level of activity in the construction industry and its stage of economic development is a complex one. Several studies over the last forty years, based mainly on cross sectional data, found a positive association between national income and several measures of the construction industry activity. early studies were concerned with the role of the construction sector, as part of physical capital, in the promotion of economic growth and development. a dominant paradigm that later emerged is the ‘Bon curve’ or the inverted U-shaped pattern of development. More recent research, based on longitudinal analysis, has also pointed to the non-linear relationship between the share of construction in GDP and the level of income per capita. Using time-series data drawn from the United nations, this study applies an econometric methodology to assess the validity of the underlying propositions in a low-middle income economy-Cape Verde—over the long period of 38 years. The findings are in line with the assumptions that in the upward growth trend in developing countries, the pattern of the construction industry tends to follow that of the general economy.

Santrauka

Ryšys tarp šalies aktyvumo statybos pramonėje lygio ir jos ekonominės plėtros stadijos yra kompleksinis. Keliais per pastaruosius keturiasdešimt metų atliktais tyrimais, paremtais daugiausia tarpsektoriniais duomenimis, nustatyti teigiami ryšiai tarp nacionalinių pajamų ir kelių statybos pramonės aktyvumo priemonių. Ankstyvieji tyrimai buvo susiję su statybos sektoriaus, kaip fizinio kapitalo dalies, vaidmeniu skatinant ekonominį augimą ir plėtrą. Vėlesnis pavyzdys yra „Bon kreivė” arba apverstos U raidės formos plėtros modelis. Naujausi tyrimai, paremti longitudine analize, taip pat buvo orientuoti į nelinijinius ryšius tarp statybosdalies BVP ir pajamų, tenkančių vienam gyventojui, lygio. Naudojantis Jungtinių Tautų duomenimis, šiame tyrime taikoma ekonometrinė metodika, kuria siekiama įvertinti pagrindinius projektus mažas ir vidutines pajamas gaunančioje valstybėje—Žaliajame Kyšulyje—per 38 metų laikotarpį. Išvados atitinka prielaidas, kad besivystančių šalių augimo tendencija, statybos pramonės modelis yra linkę sekti bendros ekonomikos tendenciją.
JUSTIFICATION OF THRUST VECTOR DEFLECTION OF TWIN-ENGINE UNMANNED AERIAL VEHICLE POWER PLANTS / DVIMOTORIO BEPILOČIO ORLAIVIO TRAUKOS VEKTORIŲ VALDYMO PAGRINDIMAS
Authors: Kulyk Mykola , Kharchenko Volodymir , Matiychyk Mykhailo
Published: April 2011

A new pattern of twin-engine power plant installation in an unmanned aerial vehicle of the conventional aerodynamic scheme is presented. Reasons for moments of harmful pitching and diving are identified and a method of elimination is suggested.

Santrauka

Pateikta nauja dviejų variklių patalpinimo schema bepiločiame orlaivyje, turinčiame normalią aerodinaminę schemą. Nustatytos pavojingų polinkio momentų priežastys bei pasiūlyti jų pašalinimo būdai.
Selection of An M184V Mutation in the Cerebrospinal Fluid of a Treatment-Naive HIV-Infected Individual Starting Darunavir-Based Therapy
Authors: Cornelissen Marion , Back Nicole KT , Burger David M , Blom Petra , Portegies Peter , Prins Jan M , van der Valk Marc
Published: April 2011

Here, we describe a newly diagnosed HIV-1-infected patient, in whom shortly after the initiation of a darunavir- based regimen, the HIV-1 virus exclusively mutated in the cerebrospinal fluid (CSF), leading to an increase in CSF HIV-1 RNA load and neurological complaints.