bluuebunny/crossref_metadata_2025_split huggingface dataset:
Symmetry considerations in the two‐fluid theory of the gradient drift instability in the lower ionosphere
Authors: Makarevich Roman A. 
Published: September 2014

AbstractA general dispersion relation for the gradient drift instability (GDI) in the lower ionosphere is derived and solved analytically for the oscillation frequency and growth rate of unstable GDI waves. The approach presented is applicable in the broad range of altitudes, both within the E region and the lower F region, and for an arbitrary background density gradient. The ion and electron fluids are treated in the same way, and linearized system of fluid equations is solved exactly, with no geometry‐ or altitude‐specific approximations required. It is demonstrated that, in the short‐wavelength limit, the GDI growth rate is maximized along the bisector between the electric current and the cross product of the gradient vector and magnetic field. This result holds at all considered altitudes, including a transitional region between the E and F regions. Symmetries of the resulting expression for the growth rate are discussed, and numerical calculations for representative gradient and current configurations are presented to illustrate and validate analytical results.
New dates for point technology in the Kimberley
Authors: Maloney Tim , O'Connor Sue , Balme Jane 
Published: September 2014

AbstractNew data from Bunuba country in the southern Kimberley provide more robust dates for point technology in the Kimberley than have been previously available. Direct percussion points have been recovered from three sites in the southern Kimberley associated with radiocarbon dates of ∼5000 calBP, whereas the earliest pressure‐flaked points are consistently associated with dates within the past 1000 years. This suggests that pressure‐flaked point technology postdates the earliest occurrence of direct percussion points by ∼4000 years in this region.
Adhesion and integration of tissue engineered cartilage to porous polyethylene for composite ear reconstruction
Authors: O'Sullivan Niamh A. , Kobayashi Shinji , Ranka Mitun P. , Zaleski Katherine L. , Yaremchuk Michael J. , Bonassar Lawrence J. , Randolph Mark A. 
Published: September 2014

AbstractThe objective of this study was to assess the ability of tissue engineered cartilage to adhere to and integrate with porous polyethylene (PPE) in vivo and to evaluate the biomechanical integrity of the bond formed at the interface. Porcine auricular, articular, and costal chondrocytes were suspended in fibrin gel polymer and placed between discs of PPE to form tri‐layer constructs. Controls consisted of fibroblasts suspended in gel or gel alone between the discs. Constructs were implanted into nude mice for 6, 12, and 18 weeks. Upon harvest, specimens were evaluated for neocartilage formation and integration into the PPE, using histological, dimensional (mass, thickness, diameter), and biomechanical (adhesion strength, interfacial stiffness, failure energy and failure strain) analyses. Neotissue was formed in all experimental constructs, consisting mostly of neocartilage integrating with discs of PPE. Control samples contained only fibrous tissue. Biomechanical analyses demonstrated that adhesion strength, interfacial stiffness, and failure energy were all significantly higher in the chondrocyte‐seeded samples than in fibroblast‐seeded controls, with the exception of costal constructs at 12 weeks, which were not significantly greater than controls. In general, failure strains did not vary between groups. In conclusion, porous polyethylene supported the growth of neocartilage that formed mechanically functional bonds with the PPE. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 983–991, 2015.
Higher Glucocorticoid Secretion in the Physiological Range Is Associated With Lower Bone Strength at the Proximal Radius in Healthy Children: Importance of Protein Intake Adjustment
Authors: Shi Lijie , Sánchez-Guijo Alberto , Hartmann Michaela F , Schönau Eckhard , Esche Jonas , Wudy Stefan A , Remer Thomas 
Published: September 2014

ABSTRACT

Whether higher production of glucocorticoids (GCs) within the physiological range may already be affecting bone status in healthy children is unknown. Because dietary protein intake affects both bone and GCs, we examined the association of urinary measures of glucocorticoid status and cortical bone in healthy non-obese children, after particularly controlling for protein intake. Proximal forearm bone parameters were measured by peripheral quantitative computed tomography (pQCT). Subjects studied (n = 175, 87 males, aged 6 to 18 years) had two 24-hour urine samples collected: the first sample at 1 year before bone measurement, and the second sample at the time of bone measurement. Major urinary GC metabolites were measured by mass spectrometry and summed to assess daily adrenal GC secretion (∑C21). Urinary free cortisol (UFF) and cortisone (UFE) were summed to assess potentially bioactive free GCs (UFF + UFE). After controlling for several covariates and especially urinary nitrogen (the biomarker of protein intake) cortisol secretion ∑C21 was inversely associated with all analyzed pQCT measures of bone quality. ∑C21 also predicted a higher endosteal and lower periosteal circumference, explaining both a smaller cortical area and (together with lower BMD) a lower strength-strain-index (SSI). UFF + UFE, UFE itself, and a urinary metabolite-estimate of 11beta-hydroxysteroid dehydrogenase type1 (11beta-HSD1) activity showed corresponding reciprocal associations (p &lt; 0.05) with BMD and bone mineral content, but not with SSI and bone geometry variables. In conclusion, higher GC levels, even within the physiological range, appear to exert negative influences on bone modeling and remodeling already during growth. Our physiological data also suggest a relevant role of cortisone as the direct source for intracrine-generated cortisol by bone cell 11beta-HSD1. © 2014 American Society for Bone and Mineral Research.
Growth and Aging of Proximal Femoral Bone: A Study With Women Spanning Three Generations
Authors: Wang Qin , Chen Decai , Cheng Shu Mei , Nicholson Patrick , Alen Markku , Cheng Sulin 
Published: September 2014

ABSTRACT

Osteoporotic hip fracture is a serious clinical event associated with high morbidity and mortality. Understanding femoral growth patterns is important for promoting bone health in the young and preventing fractures in later life. In this study, growth patterns of areal bone mineral density (aBMD) and geometric properties of the proximal femur were measured by dual-energy X-ray absorptiometry. They were studied in 251 girls from premenarche (11.2 ± 0.7 years) to late adolescence (18.3 ± 1.1 years) and compared with their premenopausal mothers (n = 128, aged 44.9 ± 4.1 years) and postmenopausal grandmothers (n = 128, aged 70.0 ± 6.3 years). Hip axis length (HAL) was the first to reach peak growth velocity (−10.5 months before menarche), followed by neck diameter (ND) and neck cross-sectional area (CSA), (−7.1 and −4.1 months before menarche, respectively). Both neck-shaft angle (NSA) and aBMD of neck and total hip peaked at menarche. At 18 years (7-year follow-up), girls already had higher femoral neck aBMD but similar HAL and NSA compared with their mothers. Grandmothers had the longest HAL, narrowest NSA, widest ND but lowest aBMD and CSA. Hip strength index (HSI), an index of femoral neck strength during a fall, dropped rapidly after menarche in girls but thereafter remained relatively constant. Grandmothers had lower HSI than either mothers or girls. In conclusion, differences in proximal femoral bone mass and structure in adulthood are largely established before menarche, indicating that heritable factors are responsible for most of the individual variance. The development of geometric properties precedes aBMD in puberty, resulting in relatively constant hip strength after menarche. This asynchronous growth leads to adaptation of bone strength to the imposed loads, avoiding fractures in a biologically efficient manner. Both deterioration of aBMD and inadequate compensatory change in bone geometry after menopause contribute to the increased fracture risk later in life. © 2014 American Society for Bone and Mineral Research.
FGF23 Is Endogenously Phosphorylated in Bone Cells
Authors: Lindberg Iris , Pang Hong Weng , Stains Joseph P , Clark David , Yang Austin J , Bonewald Lynda , Li Kevin Z 
Published: September 2014

ABSTRACT

Levels of serum phosphate are controlled by the peptide hormone FGF23, secreted from bone osteocytes. Elevated levels of circulating FGF23 are a key factor in several hypophosphatemic disorders and play a role in chronic kidney disease. Posttranslational processing of FGF23 includes multi-site O-glycosylation, which reduces intracellular cleavage by proprotein convertases. The FGF23 protein also contains four serine phosphorylation consensus sequences (S-X-D/E); in this work, we asked whether FGF23 is a substrate for secretory phosphorylation. Both HEK cells as well as IDG-SW3 cells, an osteocyte model, incorporated radiolabeled orthophosphate into intact FGF23, as well as into the 14-kDa carboxy-terminal—but not the 17-kDa N-terminal—fragment. Sequential serine-to-alanine site-directed mutagenesis of four kinase consensus sites showed that labeling occurred on three serines within the carboxy-terminal fragment, Ser180 (adjacent to the cleavage site), Ser207, and Ser212. Liquid chromatography-coupled mass spectroscopy indicated the presence of phosphate at Ser212 in recombinant R&D mouse FGF23R179Q, confirming labeling results. A phosphopeptide-specific antibody was raised against phospho-Ser212 and exhibited immunoreactivity in osteocytes present in mouse long bone, providing further evidence that FGF23 is naturally phosphorylated in bone. Bone SIBLING proteins are serine-phosphorylated by the ubiquitous Golgi secretory kinase FAM20C. Cotransfection of HEK and MC3T3 cells with FGF23 and active, but not inactive, FAM20C kinase increased the storage and release of FGF23 in radiolabeling experiments, indicating potential effects of phosphorylation on FGF23 stability. Collectively, these data point to an important role for phosphorylation of FGF23 in bone. © 2014 American Society for Bone and Mineral Research.
A novel method for mitigating the effects of dynamic coexistence on the operation of IEEE 802.15.4‐based mobile WSNs
Authors: Deylami Mohammad , Jovanov Emil 
Published: September 2014

AbstractWireless networks dynamically coexist when their transmission ranges overlap as a result of mobility. Mobile wireless sensor networks (WSNs) may suffer from significant degradation of performance due to the interference caused by dynamic coexistence, which is particularly critical for health monitoring WSNs. In this paper, we propose a novel method to detect and mitigate the harmful effects of dynamic coexistence on the operation of IEEE 802.15.4‐based mobile health monitoring WSNs. IEEE 802.15.4 uses the guaranteed time slots (GTS) mechanism to eliminate contention; however, successful transmissions cannot be guaranteed for coexisting WSNs. We show that using limited clear channel assessments at the beginning of the GTS enables the mobile WSNs to avoid collisions with minimum overhead. This method can also be used in combination with the previously proposed mechanisms for coexistence management. We analytically investigate the effects of using this method on the performance of the dynamically coexisting WSNs. We use OPNET simulation to investigate the coexistence of health monitoring WSNs and also to validate the proposed method. Our results indicate that using the proposed mechanism, 2–10 coexisting mobile WSNs with relatively high transmission rates (20–30% of maximum throughput) can achieve 20–90% higher rates of successful transmissions, with less than 10% increase in power consumption. Copyright © 2014 John Wiley & Sons, Ltd.
Stimulus–responsive ultrasound contrast agents for clinical imaging: motivations, demonstrations, and future directions
Authors: Goodwin Andrew P. , Nakatsuka Matthew A. , Mattrey Robert F. 
Published: September 2014

Microbubble ultrasound contrast agents allow imaging of the vasculature with excellent resolution and signal‐to‐noise ratios. Contrast in microbubbles derives from their interaction with an ultrasound wave to generate signal at harmonic frequencies of the stimulating pulse; subtracting the elastic echo caused by the surrounding tissue can enhance the specificity of these harmonic signals significantly. The nonlinear acoustic emission is caused by pressure‐driven microbubble size fluctuations, which in both theoretical descriptions and empirical measurements was found to depend on the mechanical properties of the shell that encapsulates the microbubble as well as stabilizes it against the surrounding aqueous environment. Thus biochemically induced switching between a rigid ‘off’ state and a flexible ‘on’ state provides a mechanism for sensing chemical markers for disease. In our research, we coupled DNA oligonucleotides to a stabilizing lipid monolayer to modulate stiffness of the shell and thereby induce stimulus–responsive behavior. In initial proof‐of‐principle studies, it was found that signal modulation came primarily from DNA crosslinks preventing the microbubble size oscillations rather than merely damping the signal. Next, these microbubbles were redesigned to include an aptamer sequence in the crosslinking strand, which not only allowed the sensing of the clotting enzyme thrombin but also provided a general strategy for sensing other soluble biomarkers in the bloodstream. Finally, the thrombin‐sensitive microbubbles were validated in a rabbit model, presenting the first example of an ultrasound contrast agent that could differentiate between active and inactive clots for the diagnosis of deep venous thrombosis. WIREs Nanomed Nanobiotechnol 2015, 7:111–123. doi: 10.1002/wnan.1285This article is categorized under:

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging
Biology-Inspired Nanomaterials > Lipid-Based Structures
Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures
Using Formative Research to Develop a Counselor Training Program for Newborn Screening in Ghana
Authors: Treadwell Marsha J. , Anie Kofi A. , Grant Althea M. , Ofori‐Acquah Solomon F. , Ohene‐Frempong Kwaku 
Published: September 2014

AbstractSickle cell disease (SCD), sickle cell trait (SCT) and related conditions are highly prevalent in sub‐Saharan Africa. Despite the public health implications, there is limited understanding of the unique needs regarding establishing and implementing extensive screening for newborns and appropriate family counseling. We sought to gain understanding of community attitudes and beliefs about SCD/SCT from counselors and potential counselors in Ghana; obtain their input about goals for counseling following newborn screening; and obtain guidance about developing effective counselor education. Five focus groups with 32 health care providers and health educators from 9 of 10 regions in Ghana were conducted by trained facilitators according to a structured protocol. Qualitative data were coded and categorized to reflect common themes. Saturation was achieved in themes related to genetics/inheritance; common complications of SCD; potential for stigmatization; marital strain; and emotional stress. Misconceptions about SCT as a form of SCD were prevalent as were cultural and spiritual beliefs about the causes of SCD/SCT. Potential positive aspects included affected children′s academic achievement as compensation for physical limitations, and family cohesion. This data informed recommendations for content and structure of a counselor training program that was provided to the Ministry of Health in Ghana.
Human papillomavirus among women with atypical squamous cells of undetermined significance in southern Brazil
Authors: Paesi Suelen , Correa Leonardo , Tregnago Márcia Caldart , Mandelli Jovana , Roesch‐Ely Mariana 
Published: September 2014

AbstractObjectiveTo determine the prevalence of atypical squamous cells of undetermined significance (ASCUS) and human papillomavirus (HPV) genotypes in a population in southern Brazil.MethodsIn a retrospective cross‐sectional study, the prevalence of ASCUS was determined among women aged 20–60 years who were referred to a private medical center in Caxias do Sul by a gynecologist for assessment of a cervical condition between January 1, 2010, and September 30, 2011. Histologic and cytologic samples were tested for HPV, and polymerase chain reaction (PCR) was used to genotype any HPV DNA identified.ResultsAmong the 250 included women, 25 (10.0%) had ASCUS. HPV DNA was found in 15 (60.0%) women with ASCUS and 115 (51.1%) of the 225 without ASCUS. Viral typing showed that 7 (46.7%) HPV‐positive women with ASCUS had multiple infections with up to five different genotypes. Both low‐ and high‐risk HPV genotypes were found in ASCUS samples; the most prevalent genotypes were HPV6/HPV11 (affecting 10 [66.7%] women), HPV51 (6 [40.0%]), and HPV16 (6 [40.0%]).ConclusionASCUS is not an indication of HPV infection. HPV screening and genotyping would benefit women with ASCUS, because treatment can be planned according to risk of carcinogenesis.
Keeping consumers in the red: Hedonic debt prioritization within multiple debt accounts
Authors: Besharat Ali , Varki Sajeev , Craig Adam W. 
Published: September 2014

AbstractIn our paper we contribute to the burgeoning literature in the psychology of debt repayment. Across three experiments, we explore the effects of the type (hedonic or utilitarian) and the timing of debt on consumers' debt repayment when managing multiple debt accounts. While prior literature has demonstrated that debtors who own multiple credit cards behave irrationally by paying down smaller balances rather than balances with higher interest rates, we found that debts incurred for hedonic purchases and in the distant past (versus proximal past) amplify this effect. The anticipated impact of debt repayment on consumption enjoyment is found to mediate this effect.
Additive impact of HER2‐/PTK6‐RNAi on interactions with HER3 or IGF‐1R leads to reduced breast cancer progression in vivo
Authors: Falkenberg Natalie , Anastasov Nataša , Höfig Ines , Bashkueva Ksenia , Lindner Katrin , Höfler Heinz , Rosemann Michael , Aubele Michaela 
Published: September 2014

The human epidermal growth factor receptor 2 (HER2) and the protein tyrosine kinase 6 (PTK6) are often co‐ and over‐expressed in invasive breast cancers. At early diagnosis, only distinct groups, such as HER2‐or hormone receptor‐positive benefit from a targeted therapy. However, a part of these tumours develops resistance within a year of administration of the drug but the majority of the patients depends on general therapies with severe side effects. A PTK6‐directed approach does not yet exist.In our present study, we successfully demonstrate, in vitro and in vivo, a significantly additive reduction of tumourigenesis of breast cancer cells simultaneously depleted of both HER2 and PTK6. In comparison with single RNAi approaches, the combined RNAi (co‐RNAi) led to a stronger reduced phosphorylation of tumour‐promoting proteins. Moreover, the co‐RNAi additively decreased cell migration as well as two and three dimensional cell proliferation in vitro. The in vivo experiments showed an additive reduction (p < 0.00001) in the growth of xenografts due to the co‐RNAi compared with HER2 or PTK6 RNAi alone. Interestingly, the complexes of HER2 or PTK6 with tumour‐relevant interaction partners, such as HER3 or the insulin‐like growth factor receptor 1 (IGF‐1R), respectively, were also reduced in xenografts although their protein expression levels were not affected following the co‐RNAi of HER2 and PTK6. Our present study reveals the potential of using combined HER2‐ and PTK6‐ knockdown as a powerful strategy for the treatment of breast cancers. Therefore, the combined inhibition of these proteins may represent an attractive tool for efficient therapy of breast cancers.
The co‐chaperone p23 promotes prostate cancer motility and metastasis
Authors: Querol Cano Laia , Lavery Derek N. , Sin Soraya , Spanjaard Emma , Brooke Greg N. , Tilman Jessica D. , Abroaf Ahmed , Gaughan Luke , Robson Craig N. , Heer Rakesh , Mauri Francesco , de Rooij Johan , Driouch Keltouma , Bevan Charlotte L. 
Published: September 2014

Prostate cancer is an androgen receptor (AR)‐dependent malignancy at initiation and progression, therefore hormone therapy is the primary line of systemic treatment. Despite initial disease regression, tumours inevitably recur and progress to an advanced castration‐resistant state a major feature of which is metastasis to the bone. Up‐regulation of AR cofactors and chaperones that overcome low hormone conditions to maintain basal AR activity has been postulated as a mechanism of therapy relapse.p23, an essential component of the apo‐AR complex, acts also after ligand binding to increase AR transcriptional activity and target gene expression, partly by increasing chromatin‐loaded holo‐receptor‐complexes. Immunohistochemical studies have demonstrated increased p23 expression in advanced prostate cancer. Here, we further characterise p23 roles in AR signalling and show that it modulates cytosolic AR levels in the absence of hormone, confirming a chaperoning function in the aporeceptor complex and suggesting p23 upregulates AR signalling at multiple stages. Moreover, p23 protein levels significantly increased upon treatment with not only androgen but also clinically relevant anti‐androgens. This was in contrast to the HSP90 inhibitor 17‐AAG, which did not modulate expression of the cochaperone – important given the HSP90‐independent roles we and others have previously described for p23.Further, we demonstrate p23 is implicated in prostate cancer cell motility and in acquisition of invasiveness capacity through the expression of specific genes known to participate in cancer progression. This may drive metastatic processes in vivo since analysis of prostate tumour biopsies revealed that high nuclear p23 significantly correlated with shorter survival times and with development of metastases in patients with lower grade tumours. We propose that increased p23 expression may allow cells to acquire a more aggressive phenotype, contributing to disease progression, and that p23 is a plausible secondary target in combination with HSP90 inhibition as a potential therapy for advanced prostate cancer.
Epitaxial growth and electronic properties of well ordered phthalocyanine heterojunctions MnPc/F16CoPc
Authors: Lindner Susi , Mahns Benjamin , Treske Uwe , Vilkov Oleg , Haidu Francisc , Fronk Michael , Zahn Dietrich R. T. , Knupfer Martin 
Published: September 2014

We have prepared phthalocyanine heterojunctions out of MnPc and F16CoPc, which were studied by means of X-ray absorption spectroscopy. This heterojunction is characterized by a charge transfer at the interface, resulting in charged MnPcδ + and F16CoPcδ − species. Our data reveal that the molecules are well ordered and oriented parallel to the substrate surface. Furthermore, we demonstrate the filling of the Co 3\documentclass[12pt]{minimal}\begin{document}$d_{z^2}$\end{document}dz2 orbital due to the charge transfer, which supports the explanation of the density functional theory, that the charge transfer is local and affects the metal centers only.
Tracing the roots of syntax with Bayesian phylogenetics
Authors: Maurits Luke , Griffiths Thomas L. 
Published: September 2014

Significance
Word order varies in a systematic way across languages. Psychological explanations have been proposed for this, but they are informed only by data on modern word-order frequencies and are unable to explain proposed patterns in historical word order change. We use novel computational techniques to make inferences about this historical change and the probable ancestral word orders of major language families. Our results simultaneously establish firm criteria for psychological explanation of word-order change and provide insight into the history of word order, informing theories of language evolution.