bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study on Self–esteem and Academic Achievement of Undergraduates
Authors: Anjali Souta , Lakshmi V. Vijaya , Kiran V. Kavitha
Published: July 2024

Having high self-esteem is one of the most important things for any person, especially for the student. It helps them to perform better in academics and to be confident in their academics. This study aims to find the relationship between the self-esteem level and academic performance of undergraduate students. It was conducted on undergraduate students of Hyderabad. The sample size was 30 and the age group of the respondents was between 18-21 years. Exploratory research design was used in the study. Stratified random sampling method was used to collect the samples.  Data was collected through interview method and further evaluated by frequency, percentage and correlation method. This study perceived that there is significant positive relationship between self-esteem level and academic performance of the undergraduates. The respondents who were having high self-esteem level were having good academic performance.
A Systematic Review of Confounders Effecting on Sudden Infant Death Syndrome (SIDS)
Authors: Noor Ayesha , Kainat Areej , Shah Ahmad Hanan , Safiyan Ahmad , Shahzadi Hira , Yousaf Iram , Akbar Muhammad Jawad , Faran Muhammad Humza , Iqbal Sana , Mustafa Eman , Chaudhary Noor-e-Hizba , Abid Abdulrehman , Iqbal Muhammad Zahid
Published: July 2024

Sudden Infant Death Syndrome (SIDS) remains the leading cause of infant mortality, affecting countries worldwide, including both wealthy and developing nations. Many confounders are responsible for SIDS, which still can be avoided, and the prevalence can stop to save infant deaths. The present systematic review has been conducted to distinguish those responsible factors. The objective of the current systematic review was to identify those confounders and corelate them with SIDS. For conducting the current systematic review, the basic online scientific data bases i.e., (Scopus, ProQuest, Science-Direct, Web of Science along with PubMed) were utilized for searching along with the manual research on Google Scholar. The present systematic review was in line with ‘Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards and recommendations. A 20-point appraisal tool for Cross-Sectional Studies (AXIS tool) was used to critically evaluate the quality of the used studies. Additionally, applying the framework of PECO-S (Population -Exposure -Comparison -Outcome -Study design) numerous observational studies were enrolled for this review. Out of 1989 studies obtained, 24 studies fulfill the inclusion criteria and are thus included in the present review. The original research studies included in the present systematic review were all in “English” language published during the time duration of 2015-2023. Overall, 24 research papers covering 11 different countries’ sample population were included. More number of infants died due to SIDS in the age group of 2-4 months. Key confounders associated with SIDS include parental smoking (64.3%), low-income status (56.9%), bed-sharing (58.7%), and non-breastfeeding (over 90%). Additionally, maternal education, genetic factors, and inequalities in living conditions were identified as significant contributors to SIDS. The review underscores the importance of targeted interventions to address these confounders, such as promoting breastfeeding, reducing parental smoking, and improving maternal education and socioeconomic conditions. By addressing these factors, the incidence of SIDS can be significantly reduced, ultimately saving the lives of infants globally.
Resistant Starch: Way to a Healthy Life
Authors: Jain Sadhna , Sinha Anamika , Rathi Ishita , Gupta Khyati , Shishodiya Neha , Kukreti Shivangi , Rath Pratingya , Kumar Alok
Published: July 2024

Prebiotic polysaccharides or resistant starches (RS) are the ones that are resistant to digestion. They are not digested by pancreatic amylase and hence do not hydrolyze D-glucose into the small intestine. One of the benefits of resistant starch is that it has a good impact on digestion activity of the digestive system, bacterial flora, LDL and HDL cholesterol, blood sugar levels, and diabetes management. Swell ability, fluidity, gelation, and water absorption are some of its desired physicochemical features that make it beneficial for many foodstuffs. The development of beneficial bacteria can be promoted with the use of food supplements containing resistant starch. It functions as a prebiotic during the fermentation of fiber and feeds beneficial bacteria present in the colon of the large intestine. Multiple kinds of resistant starch exist. Their structure or source is categorized. In one food, there might be more than one resistant starch present.
In this review, we will focus on the numerous health advantages of resistant starch and how it can help to combat the obesity, diabetes, and gut problems caused by the intake of junk food.
Immunological Approaches for Sexing Bovine Sperm: A Comprehensive Overview
Authors: Sharma Prachi , Sharma Mridula
Published: July 2024

Presently, sorting bovine sperm based on their sex has significant potential, as using sexed semen can minimize the production of excess male calves, easing the challenges of bull management. Bull semen contains approximately 50% X chromosome-bearing sperm and 50% Y chromosome-bearing sperm. The differences between these sperm types include size, weight, density, swimming speed, electrical surface charges, and protein composition. Sexed semen, which is enriched with either X or Y sperm, enables the production of offspring of a desired sex with 80–90% accuracy. This technology, developed by the USDA and patented as “Beltsville sperm sexing technology,” has been categorized under various subheadings in this review, focusing on immunological sperm sorting, proteomic profiling, biotechnological applications, and bioinformatics analysis. Immunological sperm sorting leverages the distinct proteins on the surface of X- and Y-bearing sperm. Identifying these proteins can enable the development of antibodies specific to X or Y sperm. Proteomic profiling has revealed numerous proteins differentially expressed in X and Y sperm, which could serve as markers for immunological sorting. Despite various studies, consistent success in immunological sperm sexing has been elusive. However, recent advancements in proteomic technology and bioinformatics offer promising avenues for the identification and separation of sex-specific proteins. This review delves into the history, current methods, and future directions of immunological sperm sorting, highlighting the importance of accurate protein identification and the potential of bioinformatics to enhance sperm sexing technologies.
Impact of External Electric Field on the Performance Parameters of PV Solar Cells under High Light Concentration
Authors: Boubacar Soro , Serge Tchouadep Guy , Idrissa Sourabie , Tchedre Kpeli Esso-Ehanam , Souleymane Son , Issa Zerbo , Martial Zoungrana
Published: July 2024

The performance of a photovoltaic solar cell depends on a number of external and internal factors. It then appears imperative that investigations be carried out to identify the factors favourable or unfavourable to the proper operation of the photovoltaic cell. It is in this context that we study the influence of an external variable electric field on the electric parameters of a photovoltaic solar cell under light concentration of 50 suns. After the presentation of the model of a photovoltaic solar cell used in our study and formulated the assumptions, we have established the expressions of electric parameters as function of the external electric field E0. Then, by using numerical simulation with MATCAD software, we plotted the curves of electric parameters versus the external electric field. From analysis of the curves, it appears that the short-circuit photocurrent density, electric power, fill factor and conversion efficiency increases with the increase in the intensity of the external electric field. On the other hand, it appears a drop in open circuit photovoltage and series resistance with the increase in the intensity of the external electric field.
Progesterone and estrogen responsiveness to father‐toddler interaction
Authors: Gettler Lee T. , Mcdade Thomas W. , Agustin Sonny S. , Kuzawa Christopher W.
Published: May 2013

Objectives

We assessed the responsiveness of salivary progesterone (P4) and estradiol (E2) to father‐child interaction, including testing for differences in short‐term hormonal change based on paternal characteristics. We also predicted that P4 exposure during the study period would relate positively to post‐interaction paternal mood.

Methods

We conducted an in‐home intervention study in which fathers (n = 44) played with their toddlers. Subjects provided saliva samples before interacting with their children, with additional collections 40 and 70 min later.

Results

E2 did not significantly change over the study period (P > 0.4). P4 declined significantly from baseline to 40 min (P < 0.05) and 70 min (P < 0.001). Men reporting that the interaction made them feel very happy/relaxed had greater P4 exposure from baseline through 70 min (area under the curve) compared with men reporting less positive post‐interaction mood (P < 0.05). This relationship persisted after controlling for cortisol. Men's % decrease in P4 (baseline to 40 min) was significantly greater if they had an infant (P < 0.05), while fathers' % decline in E2 (baseline to 70 min) was larger if they had more children (P < 0.05).

Conclusions

These results require replication but could indicate that grouping fathers with different levels of experience obscures meaningful variation in hormonal responses to child interaction. Our findings appear consistent with the effects of P4 as a mood enhancer and suggest future research should explore the possible role of P4 as hormonal mechanism that could reinforce or facilitate paternal investment. Am. J. Hum. Biol. 25:491–498, 2013. © 2013 Wiley Periodicals, Inc.
“One‐pot” random terpolymerization of styrene, isoprene and butadiene with Nd‐based catalyst
Authors: Li Tingting , Hu Yanming , Zhang Hongxia , Shi Zhenghai , He Gongqiang , Wang Yurong , Shen Kaihua , Li Yang
Published: May 2013

Random styrene‐isoprene‐butadiene rubber (SIBR) were achieved with the catalyst system composed of neodymium isopropoxide (Nd(OiPr)3), methylaluminoxane (MAO) and indene. This catalyst proved to be highly effective in cyclohexane even at low [Al]/[Nd] ratio (ca. 50) to give styrene‐rich terpolymer with high number‐average molecular weight (Mn) and narrow molecular weight distribution (Mw/Mn). Indene was critical to improve the coordination of styrene. High temperature was beneficial to increase the yield. Aliphatic solvents (hexane and cyclohexane) achieved a higher Mn of polymer than toluene as a solvent. The glass transition temperature (Tg) and composition of SIBR can be controlled by tuning the feed ratio of monomers. All the products have been fully characterized by NMR spectroscopy, gel permeation chromatograph (GPC), and DSC. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1772–1777, 2013
Influence of additive on structure of PVDF nanofibers electrospun via new spinneret design
Authors: Li Yi , Kotaki Masaya
Published: May 2013

Surface morphology and internal structure of polyvinylidene fluoride (PVDF) nanofibers were investigated in this study. PVDF nanofibers were electrospun by two types of spinnerets, nozzle and channel spinneret, with different contents of tetrabutylammonium chloride (TBAC) and at various take‐up velocities. The new spinneret design, channel spinneret, resulted in thicker fibers while high β‐phase content and smalld‐spacing were obtained, especially in the case of low TBAC content. And high TBAC content led to finer PVDF nanofibers with high β‐phase content and smalld‐spacing compared to low TBAC content regardless of spinneret types, while an increase in take‐up velocity did not have significant effect on both morphology and internal structure of PVDF nanofibers regardless of TBAC content. It suggests that electrostatic drawing acted dominantly rather than mechanically drawing in the system cooperating TBAC. However, the decreasing difference between two types of spinnerets was observed in terms of β‐phase content with an increase in TBAC content. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1752–1758, 2013
Investigation on multifunctional monomer modified polypropylene and its foamability
Authors: Zhang Wen , Yang Lili , Zhang Huaji , Lin Wei , Wang Yuexiang
Published: May 2013

1,6‐Hexanediol diacrylate (HDDA), pentaerythrithyl tetramethacrylate (PETMA), and triallyl‐isocyanurate (TAIC) were used as representative monomers to modify polypropylene (PP) in the presence of dicumyl peroxide (DCP) in a mixer. Fourier transformed infrared spectroscopy (FTIR) results confirmed that all the three polyfunctional monomers have been grafted on PP backbone. The shape of torque curves suggested the occurrence of grafting and/or crosslinking structure. The rheological behaviors of HDDA modified PP showed the highest G′ and lowest tan δ at low frequency, shear‐thinning shifted to lower frequency in η*–ω plot, as well as more deviation from semicircle characteristic of linear PP at high viscosity in Cole–Cole plot. And, the improvement of the mechanical properties followed the order as below: TAIC < PETMA < HDDA. Meanwhile, the foamability of the modified PP samples was also investigated. The cellular structure and morphology of the obtained foams were observed by scanning electron microscopy (SEM), and the results indicated that the foamability of the three modified PPs followed the same order, demonstrating HDDA modified PP foam possessed the highest cell density and expansion ratio, and the most well‐defined closed cell structure and uniformly cellular morphology. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1675–1681, 2013
Chain Folding Controlled by an Isomeric Repeat Unit: Helix Formation versus Random Aggregation in Acetylene‐Bridged Carbazole–Bipyridine Co‐Oligomers
Authors: Divya Kizhmuri P. , Sreejith Sivaramapanicker , Suresh Cherumuttathu H. , Philips Divya S. , Ajayaghosh Ayyappanpillai
Published: May 2013

An unprecedented, positional effect of the isomeric repeat unit on chain folding in donor–acceptor‐linked oligomers, which contain alternating bipyridine and carbazole moieties that are connected through an acetylinic linkage, is reported. 4,4′‐Linked oligomer 1 adopts an intrachain helical conformation (CD‐active) in CHCl3/MeCN (20:80 v/v), whereas oligomer 2, which contains an isomeric 6,6′‐linkage, forms interchain randomly coiled aggregates (CD‐inactive). The substitution position plays a significant role in controlling the variations in electronic effects and dipole moments around the bipyridyl moiety, which are responsible for this observed phenomenon. Two model compounds of oligomers 1 and 2 (3 and 4, respectively) were prepared and their properties were compared. A systematic investigation of the photophysical and CD properties of these structures, as well as theoretical studies, support our conclusions.
Teaching arrangements of carbohydrate metabolism in biochemistry curriculum in peking university health science center
Authors: Chen Hao , Ni Ju‐Hua
Published: May 2013

Biochemistry occupies a unique place in the medical school curricula, but the teaching of biochemistry presents certain challenges. One of these challenges is facilitating students' interest in and mastery of metabolism. The many pathways and modes of regulation can be overwhelming for students to learn and difficult for professors to teach in an engaging manner. The first chapter of the metabolism section in current Chinese biochemistry textbooks covers carbohydrate metabolism. Medical students usually complain about the difficulty of this subject. Here we discuss how to facilitate learning by rearranging the subjects in this introductory chapter of biochemical metabolism and to lay a solid foundation for future study. The strategy involves reorganizing the order in which subjects are taught from simple to complex and from short to long metabolic pathways. Most students taking the curriculum consider that the strategy engages their learning interests in biochemistry and enhances their learning outcomes. © 2013 by The International Union of Biochemistry and Molecular Biology, 41(3):139–144, 2013
The TRIPSE: A process‐oriented exam for large undergraduate classes
Authors: Nastos Stash , Rangachari P. K.
Published: May 2013

The TRIPSE (tri‐partite problem solving exercise), a process‐oriented exam that mimics the scientific process, was used previously in small classes (15–25). Provided limited data, students frame explanations and design experimental tests that they later revise with additional information. Our 6‐year experience using it with larger numbers (155–204) in a freshman biology course, suggests that it could provide a means of assessing individual student performance. Students rated the learning value of this experience to be significantly higher than a standard MCQ on a 10‐point scale (TRIPSEs 8.2, CI 8.1/8.4 vs. MCQs 4.9, CI 4.8/5.1, n = 712). Additionally, we tested one cohort (n = 146) with a group TRIPSE (groups of 6), and found that this variant also provided a valuable learning experience (8.0, CI 7.7/8.3). © 2013 by The International Union of Biochemistry and Molecular Biology, 41(3):145–155, 2013
Tanycyte‐like cells form a blood–cerebrospinal fluid barrier in the circumventricular organs of the mouse brain
Authors: Langlet Fanny , Mullier Amandine , Bouret Sebastien G. , Prevot Vincent , Dehouck Benedicte
Published: May 2013

Tanycytes are highly specialized ependymal cells that form a blood–cerebrospinal fluid (CSF) barrier at the level of the median eminence (ME), a circumventricular organ (CVO) located in the tuberal region of the hypothalamus. This ependymal layer harbors well‐organized tight junctions, a hallmark of central nervous system barriers that is lacking in the fenestrated portal vessels of the ME. The displacement of barrier properties from the vascular to the ventricular side allows the diffusion of blood‐borne molecules into the parenchyma of the ME while tanycyte tight junctions control their diffusion into the CSF, thus maintaining brain homeostasis. In the present work, we combined immunohistochemical and permeability studies to investigate the presence of tanycyte barriers along the ventricular walls of other brain CVOs. Our data indicate that, unlike cuboidal ependymal cells, ependymal cells bordering the CVOs possess long processes that project into the parenchyma of the CVOs to reach the fenestrated capillary network. Remarkably, these tanycyte‐like cells display well‐organized tight junctions around their cell bodies. Consistent with these observations, permeability studies show that this ependymal layer acts as a diffusion barrier. Together, our results suggest that tanycytes are a characteristic feature of all CVOs and yield potential new insights into their involvement in regulating the exchange between the blood, the brain, and the CSF within these “brain windows.” J. Comp. Neurol. 521:3389‐3405, 2013. © 2013 Wiley Periodicals, Inc.
Arachidonic acid closes innexin/pannexin channels and thereby inhibits microglia cell movement to a nerve injury
Authors: Samuels Stuart E. , Lipitz Jeffrey B. , Wang Junjie , Dahl Gerhard , Muller Kenneth J.
Published: May 2013

Pannexons are membrane channels formed by pannexins and are permeable to ATP. They have been implicated in various physiological and pathophysiological processes. Innexins, the invertebrate homologues of the pannexins, form innexons. Nerve injury induces calcium waves in glial cells, releasing ATP through glial pannexon/innexon channels. The ATP then activates microglia. More slowly, injury releases arachidonic acid (ArA). The present experiments show that ArA itself reduced the macroscopic membrane currents of innexin‐ and of pannexin‐injected oocytes; ArA also blocked K+‐induced release of ATP. In leeches, whose large glial cells have been favorable for studying control of microglia migration, ArA blocked glial dye‐release and, evidently, ATP‐release. A physiological consequence in the leech was block of microglial migration to nerve injuries. Exogenous ATP (100 µM) reversed the effect, for ATP causes activation and movement of microglia after nerve injury, but nitric oxide directs microglia to the lesion. It was not excluded that metabolites of ArA may also inhibit the channels. But for all these effects, ArA and its non‐metabolizable analog eicosatetraynoic acid (ETYA) were indistinguishable. Therefore, ArA itself is an endogenous regulator of pannexons and innexons. ArA thus blocks release of ATP from glia after nerve injury and thereby, at least in leeches, stops microglia at lesions. © 2013 Wiley Periodicals, Inc. Develop Neurobiol 73: 621–631, 2013
A role for synaptic zinc in ProSAP/Shank PSD scaffold malformation in autism spectrum disorders
Authors: Grabrucker Andreas M.
Published: May 2013

The establishment and maintenance of synaptic contacts as well as synaptic plasticity are crucial factors for normal brain function. The functional properties of a synapse are largely dependent on the molecular setup of synaptic proteins. Multidomain proteins of the ProSAP/Shank family act as major organizing scaffolding elements of the postsynaptic density (PSD). Interestingly, ProSAP/Shank proteins at glutamatergic synapses have been linked to a variety of Autism Spectrum Disorders (ASDs) including Phelan McDermid Syndrome, and deregulation of ProSAP/Shank has been reported in Alzheimer's disease. Although the precise molecular mechanism of the dysfunction of these proteins remains unclear, an emerging model is that mutations or deletions impair neuronal circuitry by disrupting the formation, plasticity and maturation of glutamatergic synapses. Several PSD proteins associated with ASDs are part of a complex centered around ProSAP/Shank proteins and many ProSAP/Shank interaction partners play a role in signaling within dendritic spines. Interfering with any one of the members of this signaling complex might change the output and drive the system towards synaptic dysfunction. Based on recent data, it is possible that the concerted action of ProSAP/Shank and Zn2+ is essential for the structural integrity of the PSD. This interplay might regulate postsynaptic receptor composition, but also transsynaptic signaling. It might be possible that environmental factors like nutritional Zn2+ status or metal ion homeostasis in general intersect with this distinct pathway centered around ProSAP/Shank proteins and the deregulation of any of these two factors may lead to ASDs. © 2013 The Authors. Developmental Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 74: 136–146, 2014
Proliferation of embryonic cardiomyocytes in zebrafish requires the sodium channel scn5Lab
Authors: Bennett J.S. , Stroud D.M. , Becker J.R. , Roden D.M.
Published: May 2013

In mice, homozygous deletion of the cardiac sodium channelScn5aresults in defects in cardiac morphology and embryonic death before robust sodium current can be detected. In zebrafish, morpholino knockdown of cardiac sodium channel orthologsscn5Laaandscn5Labperturbs specification of precardiac mesoderm and inhibits growth of the embryonic heart. It is not known which developmental processes are perturbed by sodium channel knockdown and whether reduced cell number is from impaired migration of cardiac progenitors into the heart, impaired myocyte proliferation, or both. We found that embryos deficient inscn5Labdisplayed defects in primary cardiogenesis specific to loss ofnkx2.5,but notnkx2.7. We generated kaede reporter fish and demonstrated that embryos treated with anti‐scn5Labmorpholino showed normal secondary differentiation of cardiomyocytes at the arterial pole between 30 and 48 h post‐fertilization. However, while proliferating myocytes were readily detected at 48 hpf in wild type embryos, there were no BrdU‐positive cardiomyocytes in embryos subjected to anti‐scn5Labtreatment. Proliferating myocytes were present in embryos injected with anti‐tnnt2morpholino to phenocopy thesilent heartmutation, and absent in embryos injected with anti‐tnnt2and anti‐scn5Labmorpholinos, indicating cardiac contraction is not required for the loss of proliferation. These data demonstrate that the role of scn5Lab in later heart growth does not involve contribution of the secondary heart field, but rather proliferation of cardiomyocytes, and appears unrelated to the role of the channel in cardiac electrogenesis. genesis 51:562–574. © 2013 Wiley Periodicals, Inc.
Composition of the essential oil from the flowers of Solandra maxima (Sessé & Moc.) P.S. Green
Authors: Radoias Georges , Bosilcov Alin
Published: May 2013

Dried flowers from Solandra maxima were hydrodistilled yielding 0.3% of essential oil; the yield could be slightly increased when the flowers were subjected to enzymatic hydrolysis using β‐glucosidase prior to hydrodistillation. The two samples were subjected to a comparative investigation by gas chromatography with flame ionization detection and gas chromatography–mass spectrometry. About 70 compounds were identified in both samples, representing more than 95% of the total. The main constituents were linalool (12.4% and 17.9%), methyl salicylate (9.1% and 11.4%), safranal (3.8% and 5.7%), α‐terpineol (2.0% and 4.5%), geraniol (2.6% and 3.6%), carvacrol (17.8% and 11.5%), (E)‐nerolidol (3.4% and 4.3%) and benzyl salicylate (11.1% and 7.1%). Alcohols, phenols and esters were the major classes, the concentration of alcohols being distinctly higher in the sample obtained after enzymatic hydrolysis. Copyright © 2013 John Wiley & Sons, Ltd.
Changes in sensory quality characteristics of coffee during storage
Authors: Kreuml Michaela T. L. , Majchrzak Dorota , Ploederl Bettina , Koenig Juergen
Published: May 2013

How long can roasted coffee beans be stored, without reducing the typical coffee flavor which is mainly responsible for consumers’ enjoyment? In Austria, most coffee packages have a best‐before date between 12 and 24 months, but it is not regulated by law. Therefore, there is the need to evaluate changes in sensory qualities of coffee beverages prepared from stored coffee beans. For preparation of the coffee beverages, the paper filter method was used. In the quantitative descriptive analysis (QDA) 10 trained assessors evaluated the intensity of 30 coffee attributes after roasting at the 9th and 18th month of storage, respectively. The sensory evaluation results showed reduction in the sensory qualities of coffee beverages after 9 months storage of roasted coffee beans. The positive associated odor and flavor attributes decreased in their intensity, whereas the negative associated odor and flavor attributes increased significantly (P < 0.05). After 18 months of storage, the rancid odor and flavor which indicate oxidation processes were even considerably perceivable. Consequently, we can assume that changes in sensory quality characteristics of roasted and vacuum‐packed coffee beans during storage are possible.
Saturn's magnetospheric refresh rate
Authors: Rymer A. M. , Mitchell D. G. , Hill T. W. , Kronberg E. A. , Krupp N. , Jackman C. M.
Published: May 2013

A 2–3 day periodicity observed in Jupiter's magnetosphere (superposed on the giant planet's 9.5 h rotation rate) has been associated with a characteristic mass‐loading/unloading period at Jupiter. We follow a method derived by Kronberg et al. () and find, consistent with their results, that this period is most likely to fall between 1.5 and 3.9 days. Assuming the same process operates at Saturn, we argue, based on equivalent scales at the two planets, that its period should be 4 to 6 times faster at Saturn and therefore display a period of 8 to 18 h. Applying the method of Kronberg et al. for the mass‐loading source rates estimated by Smith et al. () based on data from the third and fifth Cassini‐Enceladus encounters, we estimate that the expected magnetospheric refresh rate varies from 8 to 31 h, a range that includes Saturn's rotation rate of ~10.8 h. The magnetospheric period we describe is proportional to the total mass‐loading rate in the system. The period is, therefore, faster (1) for increased outgassing from Enceladus, (2) near Saturn solstice (when the highest proportion of the rings is illuminated), and (3) near solar maximum when ionization by solar photons maximizes. We do not claim to explain the few percent jitter in period derived from Saturn Kilometric Radiation with this model, nor do we address the observed difference in period observed in the north and south hemispheres.
Uncertainty in future regional sea level rise due to internal climate variability
Authors: Hu Aixue , Deser Clara
Published: May 2013

Sea level rise (SLR) is an inescapable consequence of increasing greenhouse gas concentrations, with potentially harmful effects on human populations in coastal and island regions. Observational evidence indicates that global sea level has risen in the 20th century, and climate models project an acceleration of this trend in the coming decades. Here we analyze rates of future SLR on regional scales in a 40‐member ensemble of climate change projections with the Community Climate System Model Version 3. This unique ensemble allows us to assess uncertainty in the magnitude of 21st century SLR due to internal climate variability alone. We find that simulated regional SLR at mid‐century can vary by a factor of 2 depending on location, with the North Atlantic and Pacific showing the greatest range. This uncertainty in regional SLR results primarily from internal variations in the wind‐driven and buoyancy‐driven ocean circulations.
Clinical response and tumor control based on long‐term follow‐up and patient‐reported outcomes in patients with chemodectomas of the skull base and head and neck region treated with highly conformal radiation therapy
Authors: Combs Stephanie E. , Salehi–Allameh Bahar , Habermehl Daniel , Kessel Kerstin A. , Welzel Thomas , Debus Jürgen
Published: May 2013

Background

The purpose of this study was to evaluate long‐term outcome after radiation therapy (RT) for skull base or head‐and‐neck chemodectomas.

Methods

We treated 39 patients with chemodectomas with RT. Patients were treated with either single dose stereotactic radiosurgery, fractionated stereotactic radiotherapy, or intensity modulated radiotherapy (IMRT), depending on the size and anatomy of the lesion. At primary diagnosis, 16 patients were treated with surgical resection (41%), 4 with interventional embolization (10%), and 19 with primary RT (49%). Single doses of 18 Gy/80% isodose were applied. For fractionated treatments delivered as primary RT, a median total dose of 57.6 Gy was delivered. Five patients were treated with re‐irradiation, of which 4 were treated with fractionated regimens; total dose was 28.8 Gy, 30 Gy, 40 Gy, and 56 Gy in 1.8 to 2 Gy single fractions.

Results

Clinical symptoms improved in 18 patients (46%), remained unchanged in 10 patients (26%), and worsening of sequelae was observed in only 1 patient, which was associated with tumor progression. Actuarial local control was 97% at 10 years. Overall survival was 89% at 5 years and 87% at 10 years. Deaths were not disease‐related except in 3 patients with tumor progression. No secondary malignancies were observed.

Conclusion

RT has been established as a treatment alternative for patients with glomus tumors. Long‐term local control is very high, with good clinical response to treatment. © 2013 Wiley Periodicals, Inc. Head Neck 36: 22–27, 2014
Surface water and groundwater interactions in an extensively mined watershed, upper Schuylkill River, Pennsylvania, USA
Authors: Cravotta Charles A. , Goode Daniel J. , Bartles Michael D. , Risser Dennis W. , Galeone Daniel G.
Published: May 2013

Streams crossing underground coal mines may lose flow, whereas abandoned mine drainage (AMD) restores flow downstream. During 2005–2012, discharge from the Pine Knot Mine Tunnel, the largest AMD source in the upper Schuylkill River Basin, had near‐neutral pH and elevated concentrations of iron, manganese and sulphate. Discharge from the tunnel responded rapidly to recharge but exhibited a prolonged recession compared with nearby streams, consistent with rapid infiltration of surface water and slow release of groundwater from the mine complex. Dissolved iron was attenuated downstream by oxidation and precipitation, whereas dissolved CO2degassed and pH increased. During high flow conditions, the AMD and downstream waters exhibited decreased pH, iron and sulphate with increased acidity that were modelled by mixing net‐alkaline AMD with recharge or run‐off having low ionic strength and low pH. Attenuation of dissolved iron within the river was least effective during high flow conditions because of decreased transport time coupled with inhibitory effects of low pH on oxidation kinetics.

A numerical model of groundwater flow was calibrated by using groundwater levels in the Pine Knot Mine and discharge data for the Pine Knot Mine Tunnel and West Branch Schuylkill River during a snowmelt event in January 2012. Although the calibrated model indicated substantial recharge to the mine complex took place away from streams, simulation of rapid changes in mine pool level and tunnel discharge during a high flow event in May 2012 required a source of direct recharge to the Pine Knot Mine. Such recharge produced small changes in mine pool level and rapid changes in tunnel flow rate because of extensive unsaturated storage capacity and high transmissivity within the mine complex. Thus, elimination of stream leakage could have a small effect on the annual discharge from the tunnel, but a large effect on peak discharge and associated water quality downstream. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
Probabilistic SWE reanalysis as a generalization of deterministic SWE reconstruction techniques
Authors: Girotto Manuela , Margulis Steven A. , Durand Michael
Published: May 2013

Snow accumulation and melt is highly variable in space and time in complex mountainous environments. Therefore, it is necessary to provide high‐resolution spatially and temporally distributed estimates of sub‐basin snow water equivalent (SWE) to accurately predict the timing and magnitude of snowmelt runoff. In this study, we compare two reconstruction techniques (a commonly used deterministic reconstruction vs a probabilistic data assimilation framework). The methods retrospectively estimate SWE from a time series of remotely sensed maps of fractional snow‐covered area (FSCA). In testing both methods over the Tokopah watershed in the Sierra Nevada (California), the probabilistic reconstruction approach is shown to be a more robust generalization of the deterministic reconstruction. Under idealized conditions, both probabilistic and deterministic approaches perform reasonably well and yield similar results when compared with in situ verification data, whereas the probabilistic reconstruction was found to be in slightly better agreement with snow‐pit observations. More importantly, the probabilistic approach was found to be more robust: unaccounted for biases in solar radiation impacted the probabilistic SWE estimates less than the deterministic case (4% vs 7% errors for water year (WY)1997 and 0% vs 3% errors for WY1999); the probabilistic reconstruction was found to be less sensitive to the number of available observations (6% vs 10% errors in WY1997 and 13% vs 44% errors in WY1999 from the nominal cases when four fewer FSCA images were available). Finally, results from the probabilistic reconstruction approach, which requires precipitation inputs (unlike the deterministic approach), were found to be relatively robust to bias in prior precipitation estimates, where the nominal case mean estimates were recovered even when an underestimated prior precipitation was used. The additional robustness of the probabilistic SWE reconstruction technique should prove useful in future applications over larger basins and longer periods in mountainous terrain. Copyright © 2013 John Wiley & Sons, Ltd.
Reciprocal Regulation of Cyclooxygenase 2 and Heme Oxygenase 1 upon Arsenic Trioxide Exposure in Normal Human Lung Fibroblast
Authors: Wang Qisen , Wu Lijun , Wang Jun
Published: May 2013

Detoxification enzyme heme oxygenase 1 (HO‐1) and proinflammation enzyme cyclooxygenase 2 (Cox‐2) are key response proteins that function to promote the survival of cells exposed to arsenic trioxide (ATO). However, whether there is a cross‐regulation between them in ATO‐treated cells remains poorly investigated. In this study, concomitant upregulation of Cox‐2 and HO‐1 induced by ATO was observed in normal human lung fibroblasts. Cox‐2 inhibitor NS398 suppressed the upregulation of HO‐1, whereas HO‐1 inhibitor protoporphyrin IX zinc (II) stimulated the expression of Cox‐2. Both proteins were regulated by p38, and the feedback regulation of HO‐1 on Cox‐2 was mediated through p38. Our results confirmed the reciprocal regulations between Cox‐2 and HO‐1 in ATO‐treated normal cells and shed light on the understanding of protecting cells from injury caused by ATO while simultaneously decreasing the inflammation responses, which may be related to the carcinogenicity of ATO. © 2013 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:323‐329, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.21491
PathOpt—A global transition state search approach: Outline of algorithm
Authors: Grebner Christoph , Pason Lukas P. , Engels Bernd
Published: May 2013

We propose a new algorithm to determine reaction paths and test its capability for Ar12 and Ar13 clusters. Its main ingredient is a search for the local minima on a (n−1) dimensional hyperplane (n = dimension of the complete system in Cartesian coordinates) lying perpendicular to the straight line connection between initial and final states. These minima are part of possible reaction paths and are, hence, used as starting points for an uphill search to the next transition state. First, path fragments are obtained from subsequent relaxations starting from these transition states. They can be combined with information from the straight line connection procedure to obtain complete paths. Our test computations for Ar12 and Ar13 clusters prove that PathOpt delivers several reaction paths in one round. © 2013 Wiley Periodicals, Inc.
Properties of outflow‐driven sawtooth substorms
Authors: Ouellette J. E. , Brambles O. J. , Lyon J. G. , Lotko W. , Rogers B. N.
Published: May 2013

The mechanisms by which ionospheric O+ stretches the plasma sheet causing variations in polar cap flux during magnetospheric sawtooth substorms are investigated using the multi‐fluid Lyon‐Fedder‐Mobarry simulation code. O+ outflow is induced in the simulation by Alfvénic Poynting flux flowing to low altitude during the sawtooth expansion and growth phases. The O+ fluid populates the plasma sheet and causes it to stretch tailward in response to the increased mass density. The ionospheric outflow thus functions as a feedback loop in the magnetosphere‐ionosphere system wherein O+ ions released during the expansion phase alter the magnetospheric configuration and enable the development of the next substorm. We also find that the nightside reconnection rate is strongly dependent on the position of the tail merging line. As the x‐line moves tailward, the inflow speed and magnetic field strength are reduced, creating an imbalance between dayside and nightside merging. This imbalance is responsible for the buildup and release of open magnetic flux in the magnetosphere during the sawtooth cycle.
Factors controlling early stage salt tectonics at rifted continental margins and their thermal consequences
Authors: Goteti Rajesh , Beaumont Christopher , Ings Steven J.
Published: May 2013

We use 2‐D thermomechanical models to investigate the early evolution of rifted margin salt tectonics in terms of the competition among margin tilt, salt flow, and sediment aggradation. Model experiments include initial geometry of the rifted margin and autochthonous salt basin, subsequent synrift and thermal subsidence, sediment and water loading, and sediment compaction. We also calculate the thermal evolution of the system to investigate the impact of the high thermal conductivity of the salt (halite). Model Set 1 demonstrates a two‐phase response to salt deposition: short‐term thermal equilibration between the salt and crust and longer‐term relaxation in which the salt basin thermal image penetrates to a depth on the order of its width. Set 2 addresses the competition among margin tilt, salt flow, and sediment aggradation. Set 3 examines other factors, the salt basin width and depth, and the rifted margin width, which potentially affect the system evolution. Set 4 shows that sawtooth subsalt topography, representing faulted basement grabens, does not strongly impede salt flow. The model results are discussed in terms of a ternary diagram with apices representing tilt, salt flow, and sedimentation rates. Characteristic styles include the following: (1) tilt and rapid salt flow draining salt to the distal basin before the sediment aggrades, (2) an equivalent system with faster aggradation that captures draining salt as diapirs between minibasins, and (3) rapid sediment aggradation in which diapir‐minibasins systems develop before the salt drains. Thermal consequences of these styles are discussed. A preliminary comparison shows that salt structures resembling these styles occur in the southwest Nova Scotian margin.
Sea level rise and tidal power plants in the Gulf of Maine
Authors: Pelling Holly E. , Mattias Green J. A.
Published: May 2013

The response of the Bay of Fundy and Gulf of Maine to large‐scale tidal power plants and future sea‐level rise is investigated using an established numerical tidal model. Free stream tidal turbines were simulated within the Bay of Fundy by implementing an additional bed friction term, Kt. The present‐day maximum tidal power output was determined to be 7.1 GW, and required Kt = 0.03. Extraction at this level would lead to large changes in the tidal amplitudes across the Gulf of Maine. With future SLR implemented, the energy available for extraction increases with 0.5–1 GW per m SLR. SLR simulations without tidal power extraction revealed that the response of the semidiurnal tides to SLR is highly dependent on how changes in sea level are implemented in the model. When extensive flood defenses are assumed at the present‐day coast line, the response to SLR is far larger than when land is allowed to (permanently) flood. For example, within the Bay of Fundy itself, the M2 amplitude increases with nearly 0.12 m per m SLR without flooding, but it changes with only 0.03 m per m SLR with flooding. We suggest that this is due to the flooding of land cells changing the resonant properties of the basin.
Evaluation of aerosol‐cloud interaction in the GISS ModelE using ARM observations
Authors: de Boer G. , Bauer S. E. , Toto T. , Menon Surabi , Vogelmann A. M.
Published: May 2013

Observations from the US Department of Energy's Atmospheric Radiation Measurement (ARM) program are used to evaluate the ability of the NASA GISS ModelE global climate model in reproducing observed interactions between aerosols and clouds. Included in the evaluation are comparisons of basic meteorology and aerosol properties, droplet activation, effective radius parameterizations, and surface‒based evaluations of aerosol‒cloud interactions (ACI). Differences between the simulated and observed ACI are generally large, but these differences may result partially from vertical distribution of aerosol in the model, rather than the representation of physical processes governing the interactions between aerosols and clouds. Compared to the current observations, the ModelE often features elevated droplet concentrations for a given aerosol concentration, indicating that the activation parameterizations used may be too aggressive. Additionally, parameterizations for effective radius commonly used in models were tested using ARM observations, and there was no clear superior parameterization for the cases reviewed here. This lack of consensus is demonstrated to result in potentially large, statistically significant differences to surface radiative budgets, should one parameterization be chosen over another.
The relationship between the ITCZ and the Southern Hemispheric eddy‐driven jet
Authors: Ceppi Paulo , Hwang Yen‐Ting , Liu Xiaojuan , Frierson Dargan M. W. , Hartmann Dennis L.
Published: May 2013

We study the effect of a thermal forcing confined to the midlatitudes of one hemisphere on the eddy‐driven jet in the opposite hemisphere. We demonstrate the existence of an “interhemispheric teleconnection,” whereby warming (cooling) the Northern Hemisphere causes both the intertropical convergence zone (ITCZ) and the Southern Hemispheric midlatitude jet to shift northward (southward). The interhemispheric teleconnection is effected by a change in the asymmetry of the Hadley cells: as the ITCZ shifts away from the Equator, the cross‐equatorial Hadley cell intensifies, fluxing more momentum toward the subtropics and sustaining a stronger subtropical jet. Changes in subtropical jet strength, in turn, alter the propagation of extratropical waves into the tropics, affecting eddy momentum fluxes and the eddy‐driven westerlies. The relevance of this mechanism is demonstrated in the context of future climate change simulations, where shifts of the ITCZ are significantly related to shifts of the Southern Hemispheric eddy‐driven jet in austral winter. The possible relevance of the proposed mechanism to paleoclimates is discussed, particularly with regard to theories of ice age terminations.
Impact of the dominant large‐scale teleconnections on winter temperature variability over East Asia
Authors: Lim Young‐Kwon , Kim Hae‐Dong
Published: May 2013

Monthly mean geopotential height for the past 33 DJF seasons archived in Modern Era Retrospective analysis for Research and Applications reanalysis is decomposed into the large‐scale teleconnection patterns to explain their impacts on winter temperature variability over East Asia. Following Arctic Oscillation (AO) that explains the largest variance, East Atlantic/West Russia (EA/WR), West Pacific (WP) and El Niño–Southern Oscillation (ENSO) are identified as the first four leading modes that significantly explain East Asian winter temperature variation. While the northern part of East Asia north of 50°N is prevailed by AO and EA/WR impacts, temperature in the midlatitudes (30°N–50°N), which include Mongolia, northeastern China, Shandong area, Korea, and Japan, is influenced by combined effect of the four leading teleconnections. ENSO impact on average over 33 winters is relatively weaker than the impact of the other three teleconnections. WP impact, which has received less attention than ENSO in earlier studies, characterizes winter temperatures over Korea, Japan, and central to southern China region south of 30°N mainly by advective process from the Pacific. Upper level wave activity fluxes reveal that, for the AO case, the height and circulation anomalies affecting midlatitude East Asian winter temperature is mainly located at higher latitudes north of East Asia. Distribution of the fluxes also explains that the stationary wave train associated with EA/WR propagates southeastward from the western Russia, affecting the East Asian winter temperature. Investigation on the impact of each teleconnection for the selected years reveals that the most dominant teleconnection over East Asia is not the same at all years, indicating a great deal of interannual variability. Comparison in temperature anomaly distributions between observation and temperature anomaly constructed using the combined effect of four leading teleconnections clearly show a reasonable consistency between them, demonstrating that the seasonal winter temperature distributions over East Asia are substantially explained by these four large‐scale circulation impacts.