bluuebunny/crossref_metadata_2025 huggingface dataset:
Theory of Inpatient Circadian Care (TICC): A Proposal for a Middle-Range Theory
Authors: Camargo-Sanchez Andrés , Niño Carmen L. , Sánchez Leonardo , Echeverri Sonia , Gutiérrez Diana P. , Duque Andrés F. , Pianeta Oscar , Jaramillo-Gómez Jenny A. , Pilonieta Martin A. , Cataño Nhora , Arboleda Humberto , Agostino Patricia V. , Alvarez-Baron Claudia P. , Vargas Rafael
Published: March 2015

The circadian system controls the daily rhythms of a variety of physiological processes. Most organisms show physiological, metabolic and behavioral rhythms that are coupled to environmental signals. In humans, the main synchronizer is the light/dark cycle, although non-photic cues such as food availability, noise, and work schedules are also involved. In a continuously operating hospital, the lack of rhythmicity in these elements can alter the patient’s biological rhythms and resilience. This paper presents a Theory of Inpatient Circadian Care (TICC) grounded in circadian principles. We conducted a literature search on biological rhythms, chronobiology, nursing care, and middle-range theories in the databases PubMed, SciELO Public Health, and Google Scholar. The search was performed considering a period of 6 decades from 1950 to 2013. Information was analyzed to look for links between chronobiology concepts and characteristics of inpatient care. TICC aims to integrate multidisciplinary knowledge of biomedical sciences and apply it to clinical practice in a formal way. The conceptual points of this theory are supported by abundant literature related to disease and altered biological rhythms. Our theory will be able to enrich current and future professional practice.
LETTER TO THE EDITOR Performance of the ViroSeq® HIV-1 Genotyping System v2.0 in Central Africa
Authors: Mouafo Linda Chapdeleine Mekue , Péré Hélène , Ndjoyi-Mbiguino Angélique , Koyalta Donato , Longo Jean De Dieu , Mbopi-Kéou François-Xavier , Kane Coumba Toure , Bélec Laurent
Published: March 2015

Resistance genotypes in pol gene of HIV-1 were obtained by the ViroSeq® HIV-1 Genotyping System v2.0 (Celera Diagnostics, Alameda, CA, USA) in 138 of 145 (95%) antiretroviral treatment-experienced adults in virological failure living in Central Africa (Cameroon, Central African Republic, Chad, Gabon). HIV-1 group M exhibited broad genetic diversity. Performance of the 7 ViroSeq® sequencing primers showed high failure rate, from 3% to 76% (D: 76%; F: 17%; A and H: 15%; G and B: 4%; C: 3%). These findings emphasize the need of updating the ViroSeq® HIV-1 genotyping system for non-B subtypes HIV-1.
Comparison of Rates of Death Having any Death-Certificate Mention of Heart, Kidney, or Liver Disease Among Persons Diagnosed with HIV Infection with those in the General US Population, 2009-2011
Authors: Whiteside Y. Omar , Selik Richard , An Qian , Huang Taoying , Karch Debra , Hernandez Angela L , Hall H. Irene
Published: March 2015

Objective :

Compare age-adjusted rates of death due to liver, kidney, and heart diseases during 2009-2011 among US residents diagnosed with HIV infection with those in the general population.

Methods :

Numerators were numbers of records of multiple-cause mortality data from the national vital statistics system with an ICD-10 code for the disease of interest (any mention, not necessarily the underlying cause), divided into those 1) with and 2) without an additional code for HIV infection. Denominators were 1) estimates of persons living with diagnosed HIV infection from national HIV surveillance system data and 2) general population estimates from the US Census Bureau. We compared age-adjusted rates overall (unstratified by sex, race/ethnicity, or region of residence) and stratified by demographic group.

Results :

Overall, compared with the general population, persons diagnosed with HIV infection had higher age-adjusted rates of death reported with hepatitis B (rate ratio [RR]=42.6; 95% CI: 34.7-50.7), hepatitis C (RR=19.4; 95% CI: 18.1-20.8), liver disease excluding hepatitis B or C (RR=2.1; 95% CI: 1.8-2.3), kidney disease (RR=2.4; 95% CI: 2.2-2.6), and cardiomyopathy (RR=1.9; 95% CI: 1.6-2.3), but lower rates of death reported with ischemic heart disease (RR=0.6; 95% CI: 0.6-0.7) and heart failure (RR=0.8; 95% CI: 0.6-0.9). However, the differences in rates of death reported with the heart diseases were insignificant in some demographic groups.

Conclusion :

Persons with HIV infection have a higher risk of death with liver and kidney diseases reported as causes than the general population.
Interactions between business and financial strategies in Serbian companies
Authors: Kalicanin Djordje , Todorovic Miroslav
Published: March 2015

We surveyed financial and general managers of 58 companies in Serbia in order
to examine their views on the interactions between business and financial
strategies. Although the theoretical views are well known and clear, in
practice, when there is limited availability of funding sources, a meaningful
combination of business and financial risk can be very difficult. We found
moderate interactions between business and financial strategies. Managers of
companies in Serbia are very aware of the fact that the high volatility of
operating profit suggests that they should limit borrowing. However, ordinary
practical problems in day-to-day operations, such as long periods of
collection of accounts receivable, force the companies to take additional
debt. There are significant differences between the views of managers of
large companies and managers of small businesses on how business strategy
dictates financial strategy. However, firm size is not relevant to the
current level of debt, although earlier decisions on business strategy in
terms of diversification and internationalization are relevant to the level
of leverage. Somewhat surprisingly, the current level of debt does not affect
the intended financial strategy in the sense of the managers? preferences to
take additional debt to finance possible diversification and
internationalization or other high-risk financially demanding business
strategies. As the pecking order theory advocates, managers have a strong
tendency towards internal financing.
The redistributive effects of personal taxes and social benefits in the Republic of Serbia
Authors: Djindjic Srdjan
Published: March 2015

In this paper we measure the influence of the instruments of Serbia?s fiscal
system - personal taxes (personal income tax and social security
contributions) and social benefits (means tested and nonmeans tested) - on
income redistribution, using the latest data from the Household Budget Survey
2012. We analyse the redistributive effects of the fiscal system for the year
2013 and of the fiscal system that has been functioning since 1st January
2014. We find that the redistributive effect reduces income inequality by
about 50% in both observed years. Social benefits create 98% of vertical
redistribution (2013), whereas personal taxes initiate 2% (2013). State
pensions, means-tested social benefits, and social security contributions are
most important in reducing inequality in Serbia (2013). The partial fiscal
reform (2014) has not changed the rank of the focused fiscal instruments.
White Diet: Is It Necessary During Tooth Whitening?
Authors: Matis BA , Wang G , Matis JI , Cook NB , Eckert GJ
Published: March 2015

Patients are sometimes blamed for a reduced effect of bleaching when they do not adhere to a dentist's prescribed white diet. This study aimed to determine whether a white diet is necessary by evaluating the effects of coffee, tea, wine, and dark fruits on the potential tooth whitening during the bleaching process. Each of the effects of discoloration was categorized as “yes” or “no” based on a patient questionnaire. Data from five published studies were included in the analyses. Outcomes were based on the color change between baseline and the end of bleaching. The relationships between color changes were measured subjectively and objectively. A nonwhite diet was not significantly associated with less tooth whitening, and there was only a weak positive association between tooth whitening and diet for subjects who drank large amounts of coffee/tea.
Visual Acuity and Experience with Magnification Devices in Swiss Dental Practices
Authors: Eichenberger M , Perrin P , Ramseyer S T , Lussi A
Published: March 2015

Objectives

The aims of the present study in Swiss dental practices were 1) to provide an update on the prevalence of different magnification devices, 2) to examine the relationship between self-assessed and objectively measured visual acuity, and 3) to evaluate the visual performance of dentists in the individually optimized clinical situation of their respective practices.

Methods and Materials

Sixty-nine dentists from 40 randomly selected private practices (n=20, <40 years; n=49, ≥40 years) participated in the study. A questionnaire was provided to evaluate the self-assessed near visual acuity and the experience with magnification devices. The objective near visual acuity was measured under standardized conditions on a negatoscope. The clinical situation, including the use of habitual optical aids, was evaluated with visual tests on a phantom head.

Results

A total of 64% of the dentists owned a dental loupe: 45% Galilean loupes, 16% Keplerian loupes, and 3% single lens loupes. In total, 19% of the questioned dentists owned a microscope in addition to the loupes. The correlation between the self-assessed and the objective visual performance of the dentists was weak (Spearman rank correlation coefficient=0.25). In the habitual clinical situation, magnification devices (p=0.03) and the dentist's age (p=0.0012) had a significant influence on the visual performance.

Conclusions

Many dentists were not aware of their visual handicaps. Optical aids such as loupes or microscopes should be used early enough to compensate for individual or age-related visual deficiencies.
One-year Adhesive Bond Durability to Coronal and Radicular Dentin Under Intrapulpal Pressure Simulation
Authors: El-Deeb HA , Badran O , Mobarak EH
Published: March 2015

Objective

To evaluate the microtensile bond strength (μTBS) of different adhesives to coronal vs radicular dentin after one year of storage in artificial saliva and under intrapulpal pressure (IPP) simulation.

Methods and Materials

Roots of 36 freshly extracted premolars were sectioned 5 mm apical to the cemento-enamel junction and pulp tissue was removed. Buccal enamel and cementum were trimmed to obtain standardized flat dentin surfaces. Specimens were divided into three groups (n=12/group) according to the adhesive strategies utilized: a two-step etch-and-rinse adhesive; a two-step self-etch adhesive; and a single-step self-etch adhesive. Adhesives and resin composite were applied to coronal and radicular dentin while the specimens were subjected to IPP simulation. After curing, specimens were stored in artificial saliva at 37°C in a specially constructed incubator while the IPP was maintained for either 24 hours or one year prior to testing. Bonded specimens were sectioned into sticks with a cross section of 0.8 ± 0.01 mm2 and subjected to μTBS testing. Data were statistically analyzed using multi-way analysis of variance (ANOVA) with repeated measures; one-way ANOVA tests; and Bonferroni post hoc test (p<0.05). Failure modes were determined using a scanning electron microscope at 100× magnification.

Results

ANOVA results revealed a statistically significant effect for the adhesive strategy (p<0.001) and storage period (p<0.001) as well as for their interaction (p=0.024) on the μTBS. However, dentin substrate and its interactions revealed no significant effects. For both dentin substrates, the two-step self-etch adhesive revealed statistically significantly higher μTBS values than did the other two adhesives after 24 hours and one year of storage. After one-year storage, a significant decrease in bond strength values of all tested adhesives occurred with both dentin substrates. Modes of failure were mainly adhesive and mixed.

Conclusions

Adhesives were not sensitive to structural differences between coronal and radicular dentin even after one year of storage under IPP simulation. However, all tested adhesive systems strategies were sensitive to storage.
Enamel and Dentin Microhardness and Chemical Composition After Experimental Light-activated Bleaching
Authors: Klaric E , Rakic M , Sever I , Milat O , Par M , Tarle Z
Published: March 2015

Objectives

To evaluate 1) the influence of five bleaching agents (with additional light activation) on enamel and dentin surface microhardness and chemical composition and 2) the remineralizing potential of artificial saliva and amorphous calcium phosphate (ACP).

Methods and Materials

The study was conducted on 125 human third molars dissected into quarters for separate enamel and dentin measurements. The bleaching process was performed with 38% and 25% hydrogen peroxide (HP) and 30%, 16%, and 10% carbamide peroxide (CP) gels two times for 15 minutes each time. All bleaching gels were tested alone and in combination with ZOOM2, light-emitting diode (LED), organic LED, and femtosecond laser. A total of 25 bleaching combinations (n=10) were evaluated. Microhardness was measured by a Vickers diamond. Chemical analysis was performed using energy-dispersive X-ray spectroscopy.

Results

Bleaching agents used in the absence of light activation caused a significant reduction in enamel and dentin surface microhardness (p<0.001), ranging from 8% for 16% CP to 40% for 25% HP. The effects of different light activations were negligible. After two-week treatment with ACP and artificial saliva, maximum deviation from baseline microhardness was just 3%. Such treatment increased the concentrations of calcium, phosphorus, and fluorine.

Conclusions

An increase in peroxide concentration and gel acidity negatively affected microhardness and concentrations of calcium and phosphorus in enamel and dentin. ACP and artificial saliva stimulated the remineralization of hard tissues.
The Effect of Grounding the Human Body on Mood
Authors: Chevalier Gaétan
Published: March 2015

Earthing (grounding) refers to bringing the body in contact with the Earth. Health benefits were previously reported, but no study exists about mood. This study was conducted to assess if Earthing improves mood. 40 adult participants were either grounded or sham-grounded (no grounding) for 1 hr. while relaxing in a comfortable recliner chair equipped with a conductive pillow, mat, and patches connecting them to the ground. This pilot project was double-blinded and the Brief Mood Introspection Scale (comprising 4 mood scales) was used. Pleasant and positive moods statistically significantly improved among grounded—but not sham-grounded—participants. It is concluded that the 1-hr. contact with the Earth improved mood more than expected by relaxation alone. More extensive studies are, therefore, warranted.
Effect of Ankle Weight on Blind Navigation
Authors: Paquet Nicole , Taillon-Hobson Anne , Lajoie Yves
Published: March 2015

This study tested the hypotheses that loading the ankle with a 2.3 kg weight would modify deviation (unilateral loading) and distance (unilateral and bilateral loading) during three blind navigation tasks. Ankle loading increased the distance traveled while navigating toward a previously seen target at an 8 m distance and reduced the undetected fore-aft displacement while stepping in place for 100 steps. Unilateral ankle loading had no effect on deviation during these tasks, nor in walking back and forth on an imaginary straight line. The results suggest that somatosensory cues associated with ankle loading and the increased effort to walk and step interacted with motor and cognitive functions involved in blind navigation and influenced the control of anterior-posterior body displacement.
Assessment of tree mortality on the Estonian Network of Forest Research Plots/ Puude väljalangevuse hindamine metsa kasvukäigu püsiproovitükkidel
Authors: Sims Allan , Mändma Ruth , Laarmann Diana , Korjus Henn
Published: March 2015

Assessment of tree mortality provides deeper understanding of forest structure and functioning. This enables evaluation of stand sustainability and provides information on stand productivity, diversity and health condition. Tree mortality can be assessed by spatiotemporal patterns as well as by studying the processes and causes of mortality. Tree mortality is caused by specific disturbance agents or by the complex effect of various disturbances. The purpose of this study is to examine tree mortality in Estonian forests, determine the causes of tree death, and estimate how different management regimes affect tree mortality and its causes. This study is based on 360 sample plots measured in 2003-2005 and re-measured in 2008-2010. The sample plots were divided into recently managed (RM, 146 plots) and low intensity/unmanaged (LU, 214 plots) plots based on forest management regime. In total, 53,990 trees were measured, of which 20,020 were located on RM and 33,970 on LU plots. The tree mortality for 5-year period was 3.4% on RM plots and 8.0% on LU plots. The main cause of tree mortality in RM stands was insect damage, which attributes to 29.8% of tree mortality, whereas in LU stands the main cause was tree competition, which attributes to 45.4% of tree mortality. The analysis of tree mortality indicated that an increase in relative tree diameter in both stand types contributes to an increase in mortality due to insect, wind or fungal damage and diseases. Opposite results were received with respect to competition - the smaller the tree relative diameter, the more probable it is that a tree will die because of competition with neighbouring trees. The analysis of game damage and other causes of tree mortality showed that these were not dependent on the relative diameter of trees. The analysis of the overall probability of tree mortality revealed that relatively smaller trees have a higher probability of mortality than larger trees.
Carvacrol and rosemary oil at higher concentrations induce apoptosis in human hepatoma HepG2 cells
Authors: Melušová Martina , Jantová Soňa , Horváthová Eva
Published: March 2015

Natural essential oils are volatile herbal complex compounds which manifest cytotoxic effects on living cells depending on their type and concentration but usually they are not genotoxic. Our previous studies showed that carvacrol (CA) and rosemary essential oil (RO) induced growth inhibition of both human cell lines HepG2 and BHNF-1, with hepatoma HepG2 cells being more sensitive to either compound tested. Cytotoxic concentrations of CA and RO induced the formation of DNA strand breaks. Further ex vivo studies showed that extracts prepared from hepatocytes of CA- and RO-supplemented rats did not increase incision repair activity compared to extracts from liver cells of control animals. Therefore, the aim of this work was to determine the effect of cytotoxic concentrations of CA and RO on the cell cycle and the ability of both natural volatiles to induce DNA fragmentation and apoptotic death of human hepatoma HepG2 cells. These effects were measured after 24 h incubation of HepG2 cells with CA and RO using three independent methods - flow cytometry, internucleosomal DNA fragmentation (electrophoresis) and micronucleus assay. Evaluation of morphological changes and formation of micronuclei in HepG2 cells showed no increase in the number of micronuclei in cells treated by CA and RO compared to control cells. On the other hand, CA and RO induced morphological changes typical for apoptosis in concentration-dependent manner. The presence of necrosis was negligible. Both natural compounds caused shrinking of cytoplasmic membrane and formation of apoptotic bodies. In addition, the highest concentrations of CA and RO induced internucleosomal DNA fragmentation (formation of DNA ladder) in HepG2 cells. Cell cycle analysis revealed the accumulation of cells in the G1 phase, which was accompanied by a reduction in the number of cells in the S phase after 24 h exposure to the substances tested. The cell division was thus slowed down or stopped and this process resulted in cell death
Modulation of microglial function by the antidepressant drug venlafaxine 28 November 2014
Authors: Dubovický Michal , Császár Eszter , Melicherčíková Kristína , Kuniaková Marcela , Račková Lucia
Published: March 2015

An increasing amount of data suggests that depression is an inflammatory disease. Depressed patients have higher peripheral blood levels of inflammatory markers which have been shown to access the brain and interact with the pathophysiological domain known to be involved in depression. Furthermore, microglia activation may play an important role in the inflammatory pathophysiology of depression.

In BV-2 microglia cell line, the present study investigated the potential anti-inflammatory effects of venlafaxine, along with its potential influence on injury of lipopolysaccharide (LPS)-stimulated cells. Although venlafaxine showed only marginal influence on the majority of the pro-inflammatory parameters assessed (in particular NO release, phagocytosis and proliferation), it significantly suppressed superoxide production by the stimulated cells. In addition, venlafaxine exerted also a protective effect on mitochondrial membrane potential and lysosomes of the stimulated microglia.

In conclusion, our results suggest that although VEN might have only a marginal effect on major pro-inflammatory parameters of microglia, its inhibitory effect on superoxide generation can contribute to the prevention of harmful effects of oxidative and nitrosative stress involved in the pathogenesis of depression. Moreover, the protective effect of VEN on viability of microglia can prevent a rapid reduction of these cells, thus avoiding limitations of several physiological processes in the brain and possibly also the progression of depression
Protective effect of Irvingia gabonensis stem bark extract on cadmiuminduced nephrotoxicity in rats
Authors: Ojo Oluwafemi Adeleke , Ajiboye Basiru Olaitan , Oyinloye Babatunji Emmanuel , Ojo Adebola Busola , Olarewaju Olaide Ibiwumi
Published: March 2015

Cadmium has been considered a risk factor for humans as it accumulates in body tissues, such as the liver, lungs, kidneys, bones, and reproductive organs. The aim of the present study was to evaluate the effect of Irvingia gabonensis (IG) against cadmium (Cd)- induced nephrotoxicity. The study was performed on twenty (20) male rats divided into four groups: control group, cadmium group (4 mg/kg/day, intraperitoneally), cadmium + extract (200 mg/kg body weight by oral gavage) and cadmium + extract (400 mg/kg body weight by oral gavage). Changes in the kidney biochemical markers, namely glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), aminotransferase (ALT), aspartate aminotransferase (AST) activities and levels of malondialdehyde (MDA), urea, and creatinine were determined in serum. Histological examinations were monitored. Exposure to Cd lowered the activities of kidney antioxidants, while it increased LPO levels. Levels of all disrupted parameters were alleviated by co-administration of IG extract. The malondialdehyde concentration of the rats treated with 200 and 400 mg/kg body weight of the extract significantly decreased (p<0.05) compared with the untreated cadmium rats. Yet the creatinine concentration decreased significantly (p<0.05) when the cadmium animals treated with 200 and 400 mg/kg body weight of the extract were compared with the cadmium control. Furthermore, histological alterations in the kidney were observed in cadmium untreated rats and these were ameliorated in cadmium treated rats by co-administration of IG extract. IG showed apparent protective and curative effect on Cd-induced nephrotoxicity
Preparation and performance of a colorimetric biosensor using acetylcholinesterase and indoxylacetate for assay of nerve agents and drugs
Authors: Pohanka Miroslav , Vlcek Vitezslav
Published: March 2015

Different toxic compounds can target the cholinergic nervous system. Acetylcholinesterase (AChE; EC 3.1.1.7) is one of the most crucial components of the cholinergic nervous system and thus many of the toxins interact with this enzyme. As to inhibitors, nerve agents used as chemical warfare, some insecticides, and drugs influencing the cholinergic system are common examples of AChE inhibitors. Once inhibited by a neurotoxic compound, a serious cholinergic crisis can occur. On the other hand, sensitivity of AChE to the inhibition can be used for analytical purposes. In this study, a simple disposable biosensor with AChE as a recognition element was devised. AChE was immobilized onto a cellulose matrix and indoxylacetate was used as a chromogenic substrate. The enzyme reaction was assessed by the naked eye using arbitrary units and pyridostigmine, tacrine, paraoxon, carbofuran, soman and VX were assayed as selected inhibitors. A good stability of the biosensors was found, with no aging over a quarter of a year and minimal sensitivity to the interference of organic solvents. The limit of detection ranged from 10 to 100 nmol/L for the compounds tested with a sample volume of 40 μL
Morphological Characteristics of the Stroma in Malignat Epithelial Neoplasms with Short Review of Skin Squamous Cell Carcinoma
Authors: Kakasheva-Mazhenkovska Lena , Janevska Vesna , Petrushevska Gordana , Spasevska Liljana , Basheska Neli
Published: March 2015

The stroma of the neoplasm is a highly complex structure built by: specialized mesenchymal cells typical for each tissue surroundings, cancer associated fibroblast/myofibroblast, congenital or acquired immune cells, vascular network with endothelial cells and pericytes, mastocytes, macrophages, leukocytes and adipocytes, all together incorporated in the extracellular matrix. Each neoplasm produces its own unique microenvironment where the tumor grows and modifies. Although most of the cells of the host in the stroma have compulsory tumor suppressor ability, the stroma is changing during the malignant process and it even promotes growth, invasion and metastasis. Genetic changes that occur during the development of the cancer, which are guided by the malignant cells lead to changes in the stroma of the host that will overtake it and adjust it to their own needs. In the early stages of the tumor development and invasion, the basal membrane is degraded and the stroma becomes active and contains an increased number of fibroblasts, inflammatory infiltrate and newly composed capillaries which come into direct contact with the tumor cells. These changes lead to cancer invasion.
Evaluation of the Fetal Heart Rate during Amniocentesis in Fetuses with Normal and Abnormal Karyotype
Authors: Hadzi-Lega Marija , Daneva-Markova Ana , Sozovska Eva
Published: March 2015

Introduction. We monitored the fetal heart rate (FHR) during amniocentesis in fetuses at 16-22 weeks of gestation and investigated whether an abnormal FHR was associated with chromosomal abnormalities.

Methods. This prospective study involved 600 women at 16-22 weeks of gestation who underwent genetic amniocentesis. The FHR, expressed as beats for minute, was recorded before (FHR1), immediately after (FHR2) and 60 min after (FHR3) the invasive procedure. Structural malformations detected by ultrasound and multiple pregnancy were excluded from the study.

Results. Chromosomal abnormalities have been diagnosed in 27 fetuses. Mean FHR decrease after amniocentesis has been observed in normal and in abnormal fetuses. The mean variation during amniocentesis was significant in both groups (P<0.01). The comparison between the mean FHR of the two groups showed no differences in FHR1 and FHR2 (P>0.05) but a significant difference in FHR3 (P<0.05).

Conclusion. The FHR decreased after amniocentesis; the decrease was larger in chromosomally abnormal fetuses than in normal fetuses. This difference in heart rate reaction to amniocentesis might be due to cardiac defects or developmental delay associated with the abnormal karyotype.
Power Sector and Hydropower Development in Nepal
Authors: Shrestha Rabindra Bahadur
Published: March 2015

This paper is prepared on the answer to the valuable comments made by late Jeewan P. Thanju on my article ‘Water Resources of Nepal: Misconception and Reality’ published in The Rising Nepal on January 23 & 24, 2014.The rivers of Nepal possess sufficient hydropower potentiality to enhance the country’s socio-economic development. However, some spurious expert and vested interest group exaggerated the hydro potentiality and distorted the fact of water resources development prospective in Nepal. This has created confusion among the policymakers, politician and multilateral agencies. As a result, hydropower development in Nepal has headed for wrong course, and now the power sector, the vital impetus for socio-economic development is in dire strait. This paper highlights the uniqueness and distinct technical features of Nepalese Power Sector. In this paper important component like Integrated National Power System/Grid (INPS), Power Generation Modality (Hydropower, Thermal/Nuclear Plants and Diesel Plants) are well described and Master Plan, Project Selection, Construction Schedules and Hydropower potentiality of Nepal are discussed in detail. In a severe power and energy crisis situation in the country, power export is not recommended. Nepal needs 3000 MW to reach the level of other south Asian nations. INPS is owned and operated by NEA; therefore NEA also has the responsibility to prepare master plan for power generation, transmission and distribution. But, the Department Electricity Development a regulatory body of Ministry of Energy of is undertaking / carrying out feasibility study without taking care of INPS/country’s power requirement. This has created duplication of work and confusion; as such the Ministry of Energy deviated from its responsibility of preparing sound policy, regulation and monitoring them strictly. The Ministry shouldn’t indulge in feasibility study, construction and operational activities, which come under the responsibility of concerned technical department /authority. DOI: http://dx.doi.org/10.3126/hn.v16i0.12214   HYDRO Nepal  Journal of Water Energy and EnvironmentIssue. 16, 2015, January Page: 18-22 Upload date: March 1, 2015
Climate Change and its Impact on Rice Yield
Authors: Rijal Krishna Prasad
Published: March 2015

Monsoon patterns have been changing noticeably in recent years around the globe. These changes have tremendous effects on agriculture systems especially in the areas where rainfall is the precondition of agriculture. This paper will investigate monsoon patterns in Nepal and how they correlate with recorded rice yields. The results were analyzed and cross-checked with AquaCrop, a crop water productivity model. The findings indicate that the Nepal’s monsoon patterns do not follow a definitive trend. Parameters such as onset and withdrawal dates, duration and distribution are quite unpredictable. The patterns, however, do have direct impact on national average rice yields, but that effect has turned less sensitive in recent years. The findings suggest that though monsoon has vital role on rice production in Nepal, where agriculture systems depend primarily on rainfall, more research is required to predict more accurately and precisely the production functions and relationships to yield. The better we understand this relationship, the more we can compensate for adverse monsoon patterns through anticipatory deployment of ag-technologies and advanced management options. Furthermore, support from legislators will be required to move these ideas into practice. DOI: http://dx.doi.org/10.3126/hn.v16i0.12215    HYDRO Nepal  Journal of Water Energy and EnvironmentIssue. 16, 2015, January Page: 23-27 Upload date: March 1, 2015
Addressing Deficiencies in the Highway Capacity Manual Bike Level of Service Model for Arterial Roadways
Authors: Petritsch Theodore A. , Landis Bruce W. , Scorsone Tyrone
Published: March 2015

The Highway Capacity Manual 2010 (HCM) includes methodologies for calculating the segment- and facility-level bicycle level of service (LOS) as part of a multimodal LOS analysis. Practitioners have found that, in many cases, the HCM methodology does not provide intuitive results. The HCM methodology produces scores that represent a roadway as worse than it actually is, does not provide enough sensitivity to bike facility improvements, and does not provide an adequate range of results. It is difficult to achieve an A or B LOS score with the HCM methodology. The addition of bike lanes does not have a significant impact on the LOS. It is also difficult to achieve an LOS worse than E, regardless of how poor bicycling conditions are. This paper describes an effort by the Florida Department of Transportation to create an alternative model that more accurately represents how well roadways meet the needs of bicyclists. The model is based on the time exposed and relative LOS value for each individual LOS component (intersection, link). The model was developed with the input of a panel of practitioners from around the country. The resulting model represents an LOS methodology that provides more intuitive values (than the HCM methodology) for those evaluating roadway networks. This paper provides recommended changes to the bicycle LOS methodology in the HCM chapters on urban streets.
Determining Level of Service on Freeways and Multilane Highways with Higher Speeds
Authors: Robertson James , Fitzpatrick Kay , Park Eun S. , Iragavarapu Vichika
Published: March 2015

The Highway Capacity Manual provides a means for evaluating level of service on freeways, highways, and urban streets. Presently, the Highway Capacity Manual methodology is not able to evaluate level of service on freeways with free-flow speeds greater than 75 mph or multilane highways with free-flow speeds greater than 60 mph, and many states now have facilities with posted speed limits that exceed these free-flow speeds. Recent research, conducted by the Texas A&M Transportation Institute (TTI), developed speed prediction equations for uninterrupted flow facilities with higher posted speed limits. From these equations, this paper develops procedures for calculating free-flow speed on facilities with higher posted speed limits and develops methods for estimating level of service on freeways with free-flow speeds up to 85 mph and multi lane highways with free-flow speeds up to 80 mph. For freeways, the recommendations call for utilizing the TTI speed prediction equations to calculate free-flow speed and using the calculated free-flow speeds to determine level of service from speed–flow curves developed within this paper. For multilane highways, recommendations call for utilizing the TTI speed prediction equations to calculate base free-flow speed, which is part of the equation for calculating free-flow speed, and then using the calculated free-flow speed to determine level of service from speed–flow curves developed within this paper. To aid practitioners, step-by-step procedures are provided for applying the TTI speed prediction equations within the Highway Capacity Manual methodology.
Capacity Estimation for Weaving Segments Using a Lane-Changing Model
Authors: Wang Xu , Luo Ying , Qiu Tony Z. , Yan Xinping
Published: March 2015

During peak periods, freeway bottlenecks can be activated by intensive lane changing at weaving segments, where merging and diverging areas are in close proximity. This weaving phenomenon has a major impact on capacity. Much research has been devoted to investigating capacity estimation models for weaving segments. However, because of the model parameters, estimation models are difficult to adopt directly in active traffic management strategies to estimate real-time maximum discharge flow. To this end, this study defined a linear optimization problem to solve weaving capacity and then established a lane-changing model to constrain the weaving flows. The proposed method was evaluated and analyzed for sensitivity with field data from two weaving segments on Whitemud Drive, Edmonton, Alberta, Canada. The capacity estimates from the proposed model were consistent with that from the Highway Capacity Manual 2010 model and with field observations. Moreover, it was also observed that the weaving capacity was sensitive to weaving maneuvers. Finally, the proposed method was applied to estimate the real-time maximum discharge flow rate; the estimates matched field measurements. These findings could lead to implementations in designing optimal traffic control strategies.
Estimation of Roundabout Entry Capacity under the Impact of Pedestrians by Applying Microscopic Simulation
Authors: Kang Nan , Nakamura Hideki , Asano Miho
Published: March 2015

Entry capacity is one of the most important indexes for performance evaluation of roundabouts. In addition to circulating vehicles, pedestrian flow is another key conflicting stream that has a significant impact on entry capacity. Pedestrian impact is considered by an adjustment factor in the Highway Capacity Manual 2010. However, this method is limited in estimating pedestrian impact by several influencing factors [e.g., pedestrian approaching side, farside pedestrian recognition rate (FPRR) of drivers, and physical splitter island] that are considered to be significant for representing the characteristics of the Japanese situation. The impacts of these influencing factors are examined by microscopic simulation in this study. Results from the simulation study showed that under the condition without a physical splitter island, entry capacity was reduced more significantly when more pedestrians were from the farside of the crosswalk, whereas capacity relatively increased with decreasing FPRR. Moreover, entry capacity was also increased after the installation of a physical splitter island. The significance and the necessity of a physical splitter island were demonstrated in this analysis for roundabout design and operation in Japan. This research also showed that those influencing factors (i.e., pedestrian approaching side, FPRR, and physical splitter island) should be considered in entry capacity estimation.
Temporal and Spatial Gap Acceptance for Minor Road at Uncontrolled Intersections in India
Authors: Patil Gopal R. , Pawar Digvijay S.
Published: March 2015

Capacity analysis of unsignalized intersections is done primarily with gap acceptance principles. The vehicles on lower-priority approaches maneuver when a suitable gap is available in higher-priority conflicting streams. Although temporal gaps are widely used, some researchers advocate the use of spatial gaps. The focus of this study was on analyzing temporal and spatial gaps at four-legged, partially controlled intersections in India. Unlike in developed countries, unsignalized intersections in India are not controlled with stop and yield signs with explicit priorities. The priorities are mainly set by the situations drivers perceive. Field data were collected at three four-legged intersections with video cameras. Temporal and spatial critical gaps were estimated with Raff's, logit, lag, Ashworth's, and maximum likelihood methods. The values of temporal critical gap by different methods were found to vary between 3.0 and 3.9 s. The spatial critical gap values varied from 29 to 36 m. These values were smaller than the similar values reported in developed countries, indicating aggressiveness in Indian drivers. The insights from this study can be used for the capacity analysis of unsignalized intersections in India.
Influence of Undesignated Pedestrian Crossings on Midblock Capacity of Urban Roads
Authors: Dhamaniya Ashish , Chandra Satish
Published: March 2015

Pedestrians crossing an urban road at undesignated places are not uncommon in developing countries such as India, and these people force motor vehicles to provide suitable gaps for their crossing. The present study demonstrates the effect of such crossings on the midblock capacity of an urban arterial road. Data were collected on 12 sections of six-lane urban arterial roads in three populous cities in India. Six sections were selected without any side friction to estimate the base value of capacity. The remaining six sections had pedestrian flow across roads at undesignated crossings. Speed and volume data were collected in the field and were used to estimate the capacity of a section. The base midblock capacity of a six-lane divided urban road was found to vary from 1,500 to 2,100 passenger car units per hour per lane in three cities. This variation was attributed to the different free-flow speeds in these cities. The effect of pedestrian cross flow on the midblock capacity of an urban road was evaluated by comparing the capacity of a section with pedestrian cross flow with that of the base section. Finally, a mathematical relation was developed between pedestrian cross flow and reduction in capacity. The results show practically no influence on capacity when pedestrian cross flow is less than 200 pedestrians per hour. The capacity, however, is reduced by 30% when pedestrian cross flow is increased to 1,360 pedestrians per hour.
Capacitated Centralized Carrier Collaboration Multihub Location Problem
Authors: Wang Hao , Unnikrishnan Avinash , Hernández Salvador , Cheu Ruey (Kelvin)
Published: March 2015

This study proposes a capacitated centralized carrier collaboration multihub location problem (CAP-CCCMLP) for the small- to medium-sized less-than-truckload industry, with a central entity (e.g., a third-party logistics firm) seeking a set of hybrid collaborative consolidation transshipment hubs to help establish a collaborative hybrid hub-and-spoke network that minimizes the total collaborative costs for the set of collaborating carriers in the system. A mathematical programming formulation is provided for the CAP-CCCMLP and shown to be NP-hard. The model was solved with two-phase tabu search heuristics. Computational runs were conducted to study the efficiency of the tabu search heuristic versus the CPLEX-based solution and the savings obtained through collaboration for different network sizes and maximum number of consolidation hubs. The tabu search heuristic was found to deliver significant computational savings over CPLEX and the optimality gap between the true optimal solution and the tabu search solution was found to be low for most cases. As the expected cost reduction at the shipment level needed to incentivize collaboration decreases, the likelihood that carriers will enter into collaboration increases. If the carriers expect significant cost reductions to enter into a collaborative strategy, the potential savings from the collaboration will decrease.
Simulation Framework for Modeling Large-Scale Flexible Transit Systems
Authors: Jung Jaeyoung , Jayakrishnan R.
Published: March 2015

Despite the prevalent use of simulation methods in a majority of areas in transportation research, transit and paratransit research has not relied heavily on simulation models, not only because traditional transit studies do not necessarily require simulation techniques but also because proper simulation packages are not available for modeling innovative transit systems. This study proposes a new type of simulation framework, targeting large-scale flexible transit systems with various vehicle operation schemes. The intent of this study is to describe the generalized concepts and the detailed architecture of the framework developed for urban transportation networks. A comprehensive process for the framework development, including considerations of simulation data conversion and user interface design, is discussed. Two real-time flexible transit applications are modeled with the proposed simulation framework: high coverage point-to-point transit and real-time shuttle service. Detailed simulation results are provided, and the importance of simulation design and operational features is addressed. The results also show that the framework can model realistic large networks several times faster than real time with standard desktop computers; these results raise the possibility of its use in real-time optimization schemes as well as for synchronous modeling with commercial road traffic simulators.
Initializing the Traffic Assignment Problem by Zone Aggregation and Disaggregation
Authors: Ruddell Keith , Raith Andrea
Published: March 2015

The traffic assignment problem (TAP) is a key element of many urban transport models. Given trip demand in the form of a matrix indexed by origin and destination, the TAP assigns flow to the traffic network to achieve a user equilibrium in which no individual traveler may reduce his or her trip cost by changing route. Many iterative algorithms have been developed to solve the TAP; these algorithms are usually initialized by all-or-nothing (AON) assignments in which all flow is assigned to the shortest paths and congestion is disregarded. A new method of initialization based on the solution of a simplified TAP formed by aggregating origin and destination nodes is developed. This simplified problem can be solved in a fraction of the time needed for the original problem. The user equilibrium of this aggregated problem can then be mapped onto the space of path flows of the original TAP. With a suitable choice of aggregation, the time required for an iterative TAP algorithm to converge can be greatly reduced. Including the time taken for initialization, this method gives convergence in some cases more than twice as fast as AON initialization. Methods for the automatic aggregation of origins and destinations are also proposed. The results show that the performance of path-based TAP algorithms is strongly dependent on the choice of initial solution.
Routing Policy Choice Set Generation in Stochastic Time-Dependent Networks
Authors: Ding Jing , Gao Song , Jenelius Erik , Rahmani Mahmood , Huang He , Ma Long , Pereira Francisco , Ben-Akiva Moshe
Published: March 2015

Transportation systems are inherently uncertain because of random disruptions; nevertheless, real-time information can help travelers make better route choices under such disruptions. The first revealed-preference study of routing policy choice is presented. A “routing policy” is defined as a decision rule applied at each link that maps possible realized traffic conditions to decisions to be made on the link next. The policy represents a traveler's ability to incorporate real-time information not yet available at the time of decision. Two case studies are conducted in Stockholm, Sweden, and in Singapore. Data for the underlying stochastic time-dependent network are generated from taxi GPS traces through map-matching and nonparametric link travel time estimation. An efficient algorithm to find the optimal routing policy in large-scale networks is first presented, which is a building block of any routing policy choice set generation method. The routing policy choice sets are then generated by link elimination and simulation. The generated choice sets are first evaluated on the basis of whether they include the observed traces on a specific day, or coverage. The sets are then evaluated on the basis of “adaptiveness,” defined as the capability of a routing policy to be realized as different paths over different days. A combination of link elimination and simulation methods yields satisfactory coverage. The comparison with a path choice set benchmark also suggests that a routing policy choice set could potentially provide better coverage and capture the adaptive nature of route choice.